Merge with latest upstream package version (master branch)

15 files changed, 822 insertions, 2411 deletions

diff --git a/libpkgconf/argvsplit.c b/libpkgconf/argvsplit.c
index 4e40327..4553154 100644
--- a/libpkgconf/argvsplit.c
+++ b/libpkgconf/argvsplit.c
@@ -89,18 +89,8 @@ pkgconf_argv_split(const char *src, int *argc, char ***argv)
 			}
 			else
 			{
-        /*
-         * There is no reason to keep space character escaped in fragment
-         * objects, especially given that other characters are unescaped (issue
-         * #139 is reported).
-         *
-         * Update: as a part of the issue #140 fix the backslash is now
-         * escaped as well.
-         */
-        /*
-				if (isspace((unsigned int) *src_iter) || *src_iter == '\\')
+				if (*src_iter == '\\')
 					*dst_iter++ = '\\';
-         */
 
 				*dst_iter++ = *src_iter;
 			}
diff --git a/libpkgconf/argvsplit.c.orig b/libpkgconf/argvsplit.c.orig
deleted file mode 100644
index a9e8efa..0000000
--- a/libpkgconf/argvsplit.c.orig
+++ /dev/null
@@ -1,157 +0,0 @@
-/*
- * argvsplit.c
- * argv_split() routine
- *
- * Copyright (c) 2012, 2017 pkgconf authors (see AUTHORS).
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * This software is provided 'as is' and without any warranty, express or
- * implied.  In no event shall the authors be liable for any damages arising
- * from the use of this software.
- */
-
-#include <libpkgconf/stdinc.h>
-#include <libpkgconf/libpkgconf.h>
-
-/*
- * !doc
- *
- * libpkgconf `argvsplit` module
- * =============================
- *
- * This is a lowlevel module which provides parsing of strings into argument vectors,
- * similar to what a shell would do.
- */
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_argv_free(char **argv)
- *
- *    Frees an argument vector.
- *
- *    :param char** argv: The argument vector to free.
- *    :return: nothing
- */
-void
-pkgconf_argv_free(char **argv)
-{
-	free(argv[0]);
-	free(argv);
-}
-
-/*
- * !doc
- *
- * .. c:function:: int pkgconf_argv_split(const char *src, int *argc, char ***argv)
- *
- *    Splits a string into an argument vector.
- *
- *    :param char*   src: The string to split.
- *    :param int*    argc: A pointer to an integer to store the argument count.
- *    :param char*** argv: A pointer to a pointer for an argument vector.
- *    :return: 0 on success, -1 on error.
- *    :rtype: int
- */
-int
-pkgconf_argv_split(const char *src, int *argc, char ***argv)
-{
-	char *buf = malloc(strlen(src) + 1);
-	const char *src_iter;
-	char *dst_iter;
-	int argc_count = 0;
-	int argv_size = 5;
-	char quote = 0;
-	bool escaped = false;
-
-	src_iter = src;
-	dst_iter = buf;
-
-	memset(buf, 0, strlen(src) + 1);
-
-	*argv = calloc(sizeof (void *), argv_size);
-	(*argv)[argc_count] = dst_iter;
-
-	while (*src_iter)
-	{
-		if (escaped)
-		{
-			/* POSIX: only \CHAR is special inside a double quote if CHAR is {$, `, ", \, newline}. */
-			if (quote == '\"')
-			{
-				if (!(*src_iter == '$' || *src_iter == '`' || *src_iter == '"' || *src_iter == '\\'))
-					*dst_iter++ = '\\';
-
-				*dst_iter++ = *src_iter;
-			}
-			else
-			{
-				if (isspace((unsigned int) *src_iter) || *src_iter == '\\')
-					*dst_iter++ = '\\';
-
-				*dst_iter++ = *src_iter;
-			}
-
-			escaped = false;
-		}
-		else if (quote)
-		{
-			if (*src_iter == quote)
-				quote = 0;
-			else if (*src_iter == '\\')
-				escaped = true;
-			else
-				*dst_iter++ = *src_iter;
-		}
-		else if (isspace((unsigned int)*src_iter))
-		{
-			if ((*argv)[argc_count] != NULL)
-			{
-				argc_count++, dst_iter++;
-
-				if (argc_count == argv_size)
-				{
-					argv_size += 5;
-					*argv = realloc(*argv, sizeof(void *) * argv_size);
-				}
-
-				(*argv)[argc_count] = dst_iter;
-			}
-		}
-		else switch(*src_iter)
-		{
-			case '\\':
-				escaped = true;
-				break;
-
-			case '\"':
-			case '\'':
-				quote = *src_iter;
-				break;
-
-			default:
-				*dst_iter++ = *src_iter;
-				break;
-		}
-
-		src_iter++;
-	}
-
-	if (escaped || quote)
-	{
-		free(*argv);
-		free(buf);
-		return -1;
-	}
-
-	if (strlen((*argv)[argc_count]))
-	{
-		argc_count++;
-	}
-
-	*argc = argc_count;
-	return 0;
-}
diff --git a/libpkgconf/cache.c b/libpkgconf/cache.c
index 1662ce5..7715e33 100644
--- a/libpkgconf/cache.c
+++ b/libpkgconf/cache.c
@@ -44,7 +44,7 @@
  *    :rtype: pkgconf_pkg_t *
  */
 pkgconf_pkg_t *
-pkgconf_cache_lookup(const pkgconf_client_t *client, const char *id)
+pkgconf_cache_lookup(pkgconf_client_t *client, const char *id)
 {
 	pkgconf_node_t *node;
 
@@ -134,7 +134,7 @@ pkgconf_cache_free(pkgconf_client_t *client)
 	PKGCONF_FOREACH_LIST_ENTRY_SAFE(client->pkg_cache.head, iter2, iter)
 	{
 		pkgconf_pkg_t *pkg = iter->data;
-		pkgconf_pkg_free(client, pkg);
+		pkgconf_pkg_unref(client, pkg);
 	}
 
 	memset(&client->pkg_cache, 0, sizeof client->pkg_cache);
diff --git a/libpkgconf/client.c b/libpkgconf/client.c
index f5f4717..811e043 100644
--- a/libpkgconf/client.c
+++ b/libpkgconf/client.c
@@ -324,6 +324,9 @@ pkgconf_trace(const pkgconf_client_t *client, const char *filename, size_t linen
 	size_t len;
 	va_list va;
 
+	if (client == NULL)
+		return false;
+
 	len = snprintf(errbuf, sizeof errbuf, "%s:" SIZE_FMT_SPECIFIER " [%s]: ", filename, lineno, funcname);
 
 	va_start(va, format);
diff --git a/libpkgconf/dependency.c b/libpkgconf/dependency.c
index 1a4ec68..cd01a06 100644
--- a/libpkgconf/dependency.c
+++ b/libpkgconf/dependency.c
@@ -132,6 +132,9 @@ pkgconf_dependency_free(pkgconf_list_t *list)
 	{
 		pkgconf_dependency_t *dep = node->data;
 
+		if (dep->match != NULL)
+			pkgconf_pkg_unref(NULL, dep->match);
+
 		if (dep->package != NULL)
 			free(dep->package);
 
diff --git a/libpkgconf/fragment.c b/libpkgconf/fragment.c
index 7576db7..78a3463 100644
--- a/libpkgconf/fragment.c
+++ b/libpkgconf/fragment.c
@@ -173,6 +173,7 @@ pkgconf_fragment_add(const pkgconf_client_t *client, pkgconf_list_t *list, const
 
 				free(parent->data);
 				parent->data = newdata;
+				parent->merged = true;
 
 				/* use a copy operation to force a dedup */
 				pkgconf_node_delete(&parent->iter, list);
@@ -350,7 +351,9 @@ pkgconf_fragment_copy(const pkgconf_client_t *client, pkgconf_list_t *list, cons
 	frag = calloc(sizeof(pkgconf_fragment_t), 1);
 
 	frag->type = base->type;
-	frag->data = strdup(base->data);
+	frag->merged = base->merged;
+	if (base->data != NULL)
+		frag->data = strdup(base->data);
 
 	pkgconf_node_insert_tail(&frag->iter, frag, list);
 }
@@ -383,17 +386,18 @@ pkgconf_fragment_filter(const pkgconf_client_t *client, pkgconf_list_t *dest, pk
 	}
 }
 
-static inline char *
-fragment_escape(const char *src)
+static inline bool
+fragment_should_quote(const pkgconf_fragment_t *frag)
 {
-	ssize_t outlen = strlen(src) + 10;
-	char *out = calloc(outlen, 1);
-	char *dst = out;
+	const char *src;
 
-	while (*src)
+	if (frag->data == NULL)
+		return false;
+
+	for (src = frag->data; *src; src++)
 	{
 		if (((*src < ' ') ||
-		    (*src > ' ' && *src < '$') ||
+		    (*src >= (' ' + (frag->merged ? 1 : 0)) && *src < '$') ||
 		    (*src > '$' && *src < '(') ||
 		    (*src > ')' && *src < '+') ||
 		    (*src > ':' && *src < '=') ||
@@ -402,23 +406,14 @@ fragment_escape(const char *src)
 		    (*src == '`') ||
 		    (*src > 'z' && *src < '~') ||
 		    (*src > '~')) && *src != '\\')
-			*dst++ = '\\';
-
-		*dst++ = *src++;
-
-		if ((ptrdiff_t)(dst - out) + 2 > outlen)
-		{
-			outlen *= 2;
-			out = realloc(out, outlen);
-		}
+			return true;
 	}
 
-	*dst = 0;
-	return out;
+	return false;
 }
 
 static inline size_t
-pkgconf_fragment_len(const pkgconf_fragment_t *frag, bool escape)
+pkgconf_fragment_len(const pkgconf_fragment_t *frag)
 {
 	size_t len = 1;
 
@@ -427,62 +422,37 @@ pkgconf_fragment_len(const pkgconf_fragment_t *frag, bool escape)
 
 	if (frag->data != NULL)
 	{
-		if (!escape)
-			len += strlen(frag->data);
-		else
-		{
-			char *tmp = fragment_escape(frag->data);
-			len += strlen(tmp);
-			free(tmp);
-		}
+		len += strlen(frag->data);
+
+		if (fragment_should_quote(frag))
+			len += 2;
 	}
 
 	return len;
 }
 
-/*
- * !doc
- *
- * .. c:function:: size_t pkgconf_fragment_render_len(const pkgconf_list_t *list)
- *
- *    Calculates the required memory to store a `fragment list` when rendered as a string.
- *
- *    :param pkgconf_list_t* list: The `fragment list` being rendered.
- *    :param bool escape: Whether or not to escape special shell characters.
- *    :return: the amount of bytes required to represent the `fragment list` when rendered
- *    :rtype: size_t
- */
-size_t
-pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape)
+static size_t
+fragment_render_len(const pkgconf_list_t *list, bool escape)
 {
+	(void) escape;
+
 	size_t out = 1;		/* trailing nul */
 	pkgconf_node_t *node;
 
 	PKGCONF_FOREACH_LIST_ENTRY(list->head, node)
 	{
 		const pkgconf_fragment_t *frag = node->data;
-		out += pkgconf_fragment_len(frag, escape);
+		out += pkgconf_fragment_len(frag);
 	}
 
 	return out;
 }
 
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen)
- *
- *    Renders a `fragment list` into a buffer.
- *
- *    :param pkgconf_list_t* list: The `fragment list` being rendered.
- *    :param char* buf: The buffer to render the fragment list into.
- *    :param size_t buflen: The length of the buffer.
- *    :param bool escape: Whether or not to escape special shell characters.
- *    :return: nothing
- */
-void
-pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape)
+static void
+fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape)
 {
+	(void) escape;
+
 	pkgconf_node_t *node;
 	char *bptr = buf;
 
@@ -492,10 +462,14 @@ pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen
 	{
 		const pkgconf_fragment_t *frag = node->data;
 		size_t buf_remaining = buflen - (bptr - buf);
+		bool should_quote = fragment_should_quote(frag);
 
-		if (pkgconf_fragment_len(frag, escape) > buf_remaining)
+		if (pkgconf_fragment_len(frag) > buf_remaining)
 			break;
 
+		if (should_quote)
+			*bptr++ = '\'';
+
 		if (frag->type)
 		{
 			*bptr++ = '-';
@@ -503,16 +477,10 @@ pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen
 		}
 
 		if (frag->data)
-		{
-			if (!escape)
-				bptr += pkgconf_strlcpy(bptr, frag->data, buf_remaining);
-			else
-			{
-				char *tmp = fragment_escape(frag->data);
-				bptr += pkgconf_strlcpy(bptr, tmp, buf_remaining);
-				free(tmp);
-			}
-		}
+			bptr += pkgconf_strlcpy(bptr, frag->data, buf_remaining);
+
+		if (should_quote)
+			*bptr++ = '\'';
 
 		*bptr++ = ' ';
 	}
@@ -520,6 +488,60 @@ pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen
 	*bptr = '\0';
 }
 
+static const pkgconf_fragment_render_ops_t default_render_ops = {
+	.render_len = fragment_render_len,
+	.render_buf = fragment_render_buf
+};
+
+/*
+ * !doc
+ *
+ * .. c:function:: size_t pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops)
+ *
+ *    Calculates the required memory to store a `fragment list` when rendered as a string.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` being rendered.
+ *    :param bool escape: Whether or not to escape special shell characters (deprecated).
+ *    :param pkgconf_fragment_render_ops_t* ops: An optional ops structure to use for custom renderers, else ``NULL``.
+ *    :return: the amount of bytes required to represent the `fragment list` when rendered
+ *    :rtype: size_t
+ */
+size_t
+pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops)
+{
+	(void) escape;
+
+	ops = ops != NULL ? ops : &default_render_ops;
+	return ops->render_len(list, true);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape, const pkgconf_fragment_render_ops_t *ops)
+ *
+ *    Renders a `fragment list` into a buffer.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` being rendered.
+ *    :param char* buf: The buffer to render the fragment list into.
+ *    :param size_t buflen: The length of the buffer.
+ *    :param bool escape: Whether or not to escape special shell characters (deprecated).
+ *    :param pkgconf_fragment_render_ops_t* ops: An optional ops structure to use for custom renderers, else ``NULL``.
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape, const pkgconf_fragment_render_ops_t *ops)
+{
+	(void) escape;
+
+	ops = ops != NULL ? ops : &default_render_ops;
+
+  /*
+   * The function must not return a value (issue #162 is reported).
+   */
+	ops->render_buf(list, buf, buflen, true);
+}
+
 /*
  * !doc
  *
@@ -528,17 +550,20 @@ pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen
  *    Allocate memory and render a `fragment list` into it.
  *
  *    :param pkgconf_list_t* list: The `fragment list` being rendered.
- *    :param bool escape: Whether or not to escape special shell characters.
+ *    :param bool escape: Whether or not to escape special shell characters (deprecated).
+ *    :param pkgconf_fragment_render_ops_t* ops: An optional ops structure to use for custom renderers, else ``NULL``.
  *    :return: An allocated string containing the rendered `fragment list`.
  *    :rtype: char *
  */
 char *
-pkgconf_fragment_render(const pkgconf_list_t *list, bool escape)
+pkgconf_fragment_render(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops)
 {
-	size_t buflen = pkgconf_fragment_render_len(list, escape);
+	(void) escape;
+
+	size_t buflen = pkgconf_fragment_render_len(list, true, ops);
 	char *buf = calloc(1, buflen);
 
-	pkgconf_fragment_render_buf(list, buf, buflen, escape);
+	pkgconf_fragment_render_buf(list, buf, buflen, true, ops);
 
 	return buf;
 }
diff --git a/libpkgconf/fragment.c.orig b/libpkgconf/fragment.c.orig
new file mode 100644
index 0000000..feb12f9
--- /dev/null
+++ b/libpkgconf/fragment.c.orig
@@ -0,0 +1,658 @@
+/*
+ * fragment.c
+ * Management of fragment lists.
+ *
+ * Copyright (c) 2012, 2013, 2014 pkgconf authors (see AUTHORS).
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <libpkgconf/stdinc.h>
+#include <libpkgconf/libpkgconf.h>
+
+/*
+ * !doc
+ *
+ * libpkgconf `fragment` module
+ * ============================
+ *
+ * The `fragment` module provides low-level management and rendering of fragment lists.  A
+ * `fragment list` contains various `fragments` of text (such as ``-I /usr/include``) in a matter
+ * which is composable, mergeable and reorderable.
+ */
+
+struct pkgconf_fragment_check {
+	char *token;
+	size_t len;
+};
+
+static inline bool
+pkgconf_fragment_is_unmergeable(const char *string)
+{
+	static const struct pkgconf_fragment_check check_fragments[] = {
+		{"-framework", 10},
+		{"-isystem", 8},
+		{"-idirafter", 10},
+		{"-pthread", 8},
+		{"-Wa,", 4},
+		{"-Wl,", 4},
+		{"-Wp,", 4},
+		{"-trigraphs", 10},
+		{"-pedantic", 9},
+		{"-ansi", 5},
+		{"-std=", 5},
+		{"-stdlib=", 8},
+		{"-include", 8},
+		{"-nostdinc", 9},
+		{"-nostdlibinc", 12},
+		{"-nobuiltininc", 13},
+	};
+
+	if (*string != '-')
+		return true;
+
+	for (size_t i = 0; i < PKGCONF_ARRAY_SIZE(check_fragments); i++)
+		if (!strncmp(string, check_fragments[i].token, check_fragments[i].len))
+			return true;
+
+	/* only one pair of {-flag, arg} may be merged together */
+	if (strchr(string, ' ') != NULL)
+		return false;
+
+	return false;
+}
+
+static inline bool
+pkgconf_fragment_should_munge(const char *string, const char *sysroot_dir)
+{
+	if (*string != '/')
+		return false;
+
+	if (sysroot_dir != NULL && strncmp(sysroot_dir, string, strlen(sysroot_dir)))
+		return true;
+
+	return false;
+}
+
+static inline bool
+pkgconf_fragment_is_special(const char *string)
+{
+	if (*string != '-')
+		return true;
+
+	if (!strncmp(string, "-lib:", 5))
+		return true;
+
+	return pkgconf_fragment_is_unmergeable(string);
+}
+
+static inline void
+pkgconf_fragment_munge(const pkgconf_client_t *client, char *buf, size_t buflen, const char *source, const char *sysroot_dir)
+{
+	*buf = '\0';
+
+	if (sysroot_dir == NULL)
+		sysroot_dir = pkgconf_tuple_find_global(client, "pc_sysrootdir");
+
+	if (sysroot_dir != NULL && pkgconf_fragment_should_munge(source, sysroot_dir))
+		pkgconf_strlcat(buf, sysroot_dir, buflen);
+
+	pkgconf_strlcat(buf, source, buflen);
+
+	if (*buf == '/' && !(client->flags & PKGCONF_PKG_PKGF_DONT_RELOCATE_PATHS))
+		pkgconf_path_relocate(buf, buflen);
+}
+
+static inline char *
+pkgconf_fragment_copy_munged(const pkgconf_client_t *client, const char *source)
+{
+	char mungebuf[PKGCONF_ITEM_SIZE];
+	pkgconf_fragment_munge(client, mungebuf, sizeof mungebuf, source, client->sysroot_dir);
+	return strdup(mungebuf);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_add(const pkgconf_client_t *client, pkgconf_list_t *list, const char *string)
+ *
+ *    Adds a `fragment` of text to a `fragment list`, possibly modifying the fragment if a sysroot is set.
+ *
+ *    :param pkgconf_client_t* client: The pkgconf client being accessed.
+ *    :param pkgconf_list_t* list: The fragment list.
+ *    :param char* string: The string of text to add as a fragment to the fragment list.
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_add(const pkgconf_client_t *client, pkgconf_list_t *list, const char *string)
+{
+	pkgconf_fragment_t *frag;
+
+	if (*string == '\0')
+		return;
+
+	if (!pkgconf_fragment_is_special(string))
+	{
+		frag = calloc(sizeof(pkgconf_fragment_t), 1);
+
+		frag->type = *(string + 1);
+		frag->data = pkgconf_fragment_copy_munged(client, string + 2);
+
+		PKGCONF_TRACE(client, "added fragment {%c, '%s'} to list @%p", frag->type, frag->data, list);
+	}
+	else
+	{
+		char mungebuf[PKGCONF_ITEM_SIZE];
+
+		if (list->tail != NULL && list->tail->data != NULL)
+		{
+			pkgconf_fragment_t *parent = list->tail->data;
+
+			/* only attempt to merge 'special' fragments together */
+			if (!parent->type && pkgconf_fragment_is_unmergeable(parent->data))
+			{
+				size_t len;
+				char *newdata;
+
+				pkgconf_fragment_munge(client, mungebuf, sizeof mungebuf, string, NULL);
+
+				len = strlen(parent->data) + strlen(mungebuf) + 2;
+				newdata = malloc(len);
+
+				pkgconf_strlcpy(newdata, parent->data, len);
+				pkgconf_strlcat(newdata, " ", len);
+				pkgconf_strlcat(newdata, mungebuf, len);
+
+				PKGCONF_TRACE(client, "merging '%s' to '%s' to form fragment {'%s'} in list @%p", mungebuf, parent->data, newdata, list);
+
+				free(parent->data);
+				parent->data = newdata;
+				parent->merged = true;
+
+				/* use a copy operation to force a dedup */
+				pkgconf_node_delete(&parent->iter, list);
+				pkgconf_fragment_copy(client, list, parent, false);
+
+				/* the fragment list now (maybe) has the copied node, so free the original */
+				free(parent->data);
+				free(parent);
+
+				return;
+			}
+		}
+
+		frag = calloc(sizeof(pkgconf_fragment_t), 1);
+
+		frag->type = 0;
+		frag->data = strdup(string);
+
+		PKGCONF_TRACE(client, "created special fragment {'%s'} in list @%p", frag->data, list);
+	}
+
+	pkgconf_node_insert_tail(&frag->iter, frag, list);
+}
+
+static inline pkgconf_fragment_t *
+pkgconf_fragment_lookup(pkgconf_list_t *list, const pkgconf_fragment_t *base)
+{
+	pkgconf_node_t *node;
+
+	PKGCONF_FOREACH_LIST_ENTRY_REVERSE(list->tail, node)
+	{
+		pkgconf_fragment_t *frag = node->data;
+
+		if (base->type != frag->type)
+			continue;
+
+		if (!strcmp(base->data, frag->data))
+			return frag;
+	}
+
+	return NULL;
+}
+
+static inline bool
+pkgconf_fragment_can_merge_back(const pkgconf_fragment_t *base, unsigned int flags, bool is_private)
+{
+	(void) flags;
+
+	if (base->type == 'l')
+	{
+		if (is_private)
+			return false;
+
+		return true;
+	}
+
+	if (base->type == 'F')
+		return false;
+	if (base->type == 'L')
+		return false;
+	if (base->type == 'I')
+		return false;
+
+	return true;
+}
+
+static inline bool
+pkgconf_fragment_can_merge(const pkgconf_fragment_t *base, unsigned int flags, bool is_private)
+{
+	(void) flags;
+
+	if (is_private)
+		return false;
+
+	return pkgconf_fragment_is_unmergeable(base->data);
+}
+
+static inline pkgconf_fragment_t *
+pkgconf_fragment_exists(pkgconf_list_t *list, const pkgconf_fragment_t *base, unsigned int flags, bool is_private)
+{
+	if (!pkgconf_fragment_can_merge_back(base, flags, is_private))
+		return NULL;
+
+	if (!pkgconf_fragment_can_merge(base, flags, is_private))
+		return NULL;
+
+	return pkgconf_fragment_lookup(list, base);
+}
+
+static inline bool
+pkgconf_fragment_should_merge(const pkgconf_fragment_t *base)
+{
+	const pkgconf_fragment_t *parent;
+
+	/* if we are the first fragment, that means the next fragment is the same, so it's always safe. */
+	if (base->iter.prev == NULL)
+		return true;
+
+	/* this really shouldn't ever happen, but handle it */
+	parent = base->iter.prev->data;
+	if (parent == NULL)
+		return true;
+
+	switch (parent->type)
+	{
+	case 'l':
+	case 'L':
+	case 'I':
+		return true;
+	default:
+		return !base->type || parent->type == base->type;
+	}
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: bool pkgconf_fragment_has_system_dir(const pkgconf_client_t *client, const pkgconf_fragment_t *frag)
+ *
+ *    Checks if a `fragment` contains a `system path`.  System paths are detected at compile time and optionally overridden by
+ *    the ``PKG_CONFIG_SYSTEM_INCLUDE_PATH`` and ``PKG_CONFIG_SYSTEM_LIBRARY_PATH`` environment variables.
+ *
+ *    :param pkgconf_client_t* client: The pkgconf client object the fragment belongs to.
+ *    :param pkgconf_fragment_t* frag: The fragment being checked.
+ *    :return: true if the fragment contains a system path, else false
+ *    :rtype: bool
+ */
+bool
+pkgconf_fragment_has_system_dir(const pkgconf_client_t *client, const pkgconf_fragment_t *frag)
+{
+	const pkgconf_list_t *check_paths = NULL;
+
+	switch (frag->type)
+	{
+	case 'L':
+		check_paths = &client->filter_libdirs;
+		break;
+	case 'I':
+		check_paths = &client->filter_includedirs;
+		break;
+	default:
+		return false;
+	}
+
+	return pkgconf_path_match_list(frag->data, check_paths);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_copy(const pkgconf_client_t *client, pkgconf_list_t *list, const pkgconf_fragment_t *base, bool is_private)
+ *
+ *    Copies a `fragment` to another `fragment list`, possibly removing a previous copy of the `fragment`
+ *    in a process known as `mergeback`.
+ *
+ *    :param pkgconf_client_t* client: The pkgconf client being accessed.
+ *    :param pkgconf_list_t* list: The list the fragment is being added to.
+ *    :param pkgconf_fragment_t* base: The fragment being copied.
+ *    :param bool is_private: Whether the fragment list is a `private` fragment list (static linking).
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_copy(const pkgconf_client_t *client, pkgconf_list_t *list, const pkgconf_fragment_t *base, bool is_private)
+{
+	pkgconf_fragment_t *frag;
+
+	if ((frag = pkgconf_fragment_exists(list, base, client->flags, is_private)) != NULL)
+	{
+		if (pkgconf_fragment_should_merge(frag))
+			pkgconf_fragment_delete(list, frag);
+	}
+	else if (!is_private && !pkgconf_fragment_can_merge_back(base, client->flags, is_private) && (pkgconf_fragment_lookup(list, base) != NULL))
+		return;
+
+	frag = calloc(sizeof(pkgconf_fragment_t), 1);
+
+	frag->type = base->type;
+	frag->merged = base->merged;
+	if (base->data != NULL)
+		frag->data = strdup(base->data);
+
+	pkgconf_node_insert_tail(&frag->iter, frag, list);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_filter(const pkgconf_client_t *client, pkgconf_list_t *dest, pkgconf_list_t *src, pkgconf_fragment_filter_func_t filter_func)
+ *
+ *    Copies a `fragment list` to another `fragment list` which match a user-specified filtering function.
+ *
+ *    :param pkgconf_client_t* client: The pkgconf client being accessed.
+ *    :param pkgconf_list_t* dest: The destination list.
+ *    :param pkgconf_list_t* src: The source list.
+ *    :param pkgconf_fragment_filter_func_t filter_func: The filter function to use.
+ *    :param void* data: Optional data to pass to the filter function.
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_filter(const pkgconf_client_t *client, pkgconf_list_t *dest, pkgconf_list_t *src, pkgconf_fragment_filter_func_t filter_func, void *data)
+{
+	pkgconf_node_t *node;
+
+	PKGCONF_FOREACH_LIST_ENTRY(src->head, node)
+	{
+		pkgconf_fragment_t *frag = node->data;
+
+		if (filter_func(client, frag, data))
+			pkgconf_fragment_copy(client, dest, frag, true);
+	}
+}
+
+static inline bool
+fragment_should_quote(const pkgconf_fragment_t *frag)
+{
+	const char *src;
+
+	if (frag->data == NULL)
+		return false;
+
+	for (src = frag->data; *src; src++)
+	{
+		if (((*src < ' ') ||
+		    (*src >= (' ' + (frag->merged ? 1 : 0)) && *src < '$') ||
+		    (*src > '$' && *src < '(') ||
+		    (*src > ')' && *src < '+') ||
+		    (*src > ':' && *src < '=') ||
+		    (*src > '=' && *src < '@') ||
+		    (*src > 'Z' && *src < '^') ||
+		    (*src == '`') ||
+		    (*src > 'z' && *src < '~') ||
+		    (*src > '~')) && *src != '\\')
+			return true;
+	}
+
+	return false;
+}
+
+static inline size_t
+pkgconf_fragment_len(const pkgconf_fragment_t *frag)
+{
+	size_t len = 1;
+
+	if (frag->type)
+		len += 2;
+
+	if (frag->data != NULL)
+	{
+		len += strlen(frag->data);
+
+		if (fragment_should_quote(frag))
+			len += 2;
+	}
+
+	return len;
+}
+
+static size_t
+fragment_render_len(const pkgconf_list_t *list, bool escape)
+{
+	(void) escape;
+
+	size_t out = 1;		/* trailing nul */
+	pkgconf_node_t *node;
+
+	PKGCONF_FOREACH_LIST_ENTRY(list->head, node)
+	{
+		const pkgconf_fragment_t *frag = node->data;
+		out += pkgconf_fragment_len(frag);
+	}
+
+	return out;
+}
+
+static void
+fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape)
+{
+	(void) escape;
+
+	pkgconf_node_t *node;
+	char *bptr = buf;
+
+	memset(buf, 0, buflen);
+
+	PKGCONF_FOREACH_LIST_ENTRY(list->head, node)
+	{
+		const pkgconf_fragment_t *frag = node->data;
+		size_t buf_remaining = buflen - (bptr - buf);
+		bool should_quote = fragment_should_quote(frag);
+
+		if (pkgconf_fragment_len(frag) > buf_remaining)
+			break;
+
+		if (should_quote)
+			*bptr++ = '\'';
+
+		if (frag->type)
+		{
+			*bptr++ = '-';
+			*bptr++ = frag->type;
+		}
+
+		if (frag->data)
+			bptr += pkgconf_strlcpy(bptr, frag->data, buf_remaining);
+
+		if (should_quote)
+			*bptr++ = '\'';
+
+		*bptr++ = ' ';
+	}
+
+	*bptr = '\0';
+}
+
+static const pkgconf_fragment_render_ops_t default_render_ops = {
+	.render_len = fragment_render_len,
+	.render_buf = fragment_render_buf
+};
+
+/*
+ * !doc
+ *
+ * .. c:function:: size_t pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops)
+ *
+ *    Calculates the required memory to store a `fragment list` when rendered as a string.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` being rendered.
+ *    :param bool escape: Whether or not to escape special shell characters (deprecated).
+ *    :param pkgconf_fragment_render_ops_t* ops: An optional ops structure to use for custom renderers, else ``NULL``.
+ *    :return: the amount of bytes required to represent the `fragment list` when rendered
+ *    :rtype: size_t
+ */
+size_t
+pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops)
+{
+	(void) escape;
+
+	ops = ops != NULL ? ops : &default_render_ops;
+	return ops->render_len(list, true);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape, const pkgconf_fragment_render_ops_t *ops)
+ *
+ *    Renders a `fragment list` into a buffer.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` being rendered.
+ *    :param char* buf: The buffer to render the fragment list into.
+ *    :param size_t buflen: The length of the buffer.
+ *    :param bool escape: Whether or not to escape special shell characters (deprecated).
+ *    :param pkgconf_fragment_render_ops_t* ops: An optional ops structure to use for custom renderers, else ``NULL``.
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t buflen, bool escape, const pkgconf_fragment_render_ops_t *ops)
+{
+	(void) escape;
+
+	ops = ops != NULL ? ops : &default_render_ops;
+	return ops->render_buf(list, buf, buflen, true);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: char *pkgconf_fragment_render(const pkgconf_list_t *list)
+ *
+ *    Allocate memory and render a `fragment list` into it.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` being rendered.
+ *    :param bool escape: Whether or not to escape special shell characters (deprecated).
+ *    :param pkgconf_fragment_render_ops_t* ops: An optional ops structure to use for custom renderers, else ``NULL``.
+ *    :return: An allocated string containing the rendered `fragment list`.
+ *    :rtype: char *
+ */
+char *
+pkgconf_fragment_render(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops)
+{
+	(void) escape;
+
+	size_t buflen = pkgconf_fragment_render_len(list, true, ops);
+	char *buf = calloc(1, buflen);
+
+	pkgconf_fragment_render_buf(list, buf, buflen, true, ops);
+
+	return buf;
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_delete(pkgconf_list_t *list, pkgconf_fragment_t *node)
+ *
+ *    Delete a `fragment node` from a `fragment list`.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` to delete from.
+ *    :param pkgconf_fragment_t* node: The `fragment node` to delete.
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_delete(pkgconf_list_t *list, pkgconf_fragment_t *node)
+{
+	pkgconf_node_delete(&node->iter, list);
+
+	free(node->data);
+	free(node);
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: void pkgconf_fragment_free(pkgconf_list_t *list)
+ *
+ *    Delete an entire `fragment list`.
+ *
+ *    :param pkgconf_list_t* list: The `fragment list` to delete.
+ *    :return: nothing
+ */
+void
+pkgconf_fragment_free(pkgconf_list_t *list)
+{
+	pkgconf_node_t *node, *next;
+
+	PKGCONF_FOREACH_LIST_ENTRY_SAFE(list->head, next, node)
+	{
+		pkgconf_fragment_t *frag = node->data;
+
+		free(frag->data);
+		free(frag);
+	}
+}
+
+/*
+ * !doc
+ *
+ * .. c:function:: bool pkgconf_fragment_parse(const pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_list_t *vars, const char *value)
+ *
+ *    Parse a string into a `fragment list`.
+ *
+ *    :param pkgconf_client_t* client: The pkgconf client being accessed.
+ *    :param pkgconf_list_t* list: The `fragment list` to add the fragment entries to.
+ *    :param pkgconf_list_t* vars: A list of variables to use for variable substitution.
+ *    :param char* value: The string to parse into fragments.
+ *    :return: true on success, false on parse error
+ */
+bool
+pkgconf_fragment_parse(const pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_list_t *vars, const char *value)
+{
+	int i, ret, argc;
+	char **argv;
+	char *repstr = pkgconf_tuple_parse(client, vars, value);
+
+	PKGCONF_TRACE(client, "post-subst: [%s] -> [%s]", value, repstr);
+
+	ret = pkgconf_argv_split(repstr, &argc, &argv);
+	if (ret < 0)
+	{
+		PKGCONF_TRACE(client, "unable to parse fragment string [%s]", repstr);
+		free(repstr);
+		return false;
+	}
+
+	for (i = 0; i < argc; i++)
+	{
+		if (argv[i] == NULL)
+		{
+			PKGCONF_TRACE(client, "parsed fragment string is inconsistent: argc = %d while argv[%d] == NULL", argc, i);
+			pkgconf_argv_free(argv);
+			free(repstr);
+			return false;
+		}
+
+		pkgconf_fragment_add(client, list, argv[i]);
+	}
+
+	pkgconf_argv_free(argv);
+	free(repstr);
+
+	return true;
+}
diff --git a/libpkgconf/libpkgconf.h b/libpkgconf/libpkgconf.h
index b07ec68..0e8d83e 100644
--- a/libpkgconf/libpkgconf.h
+++ b/libpkgconf/libpkgconf.h
@@ -78,6 +78,8 @@ struct pkgconf_fragment_ {
 
 	char type;
 	char *data;
+
+	bool merged;
 };
 
 struct pkgconf_dependency_ {
@@ -87,6 +89,7 @@ struct pkgconf_dependency_ {
 	pkgconf_pkg_comparator_t compare;
 	char *version;
 	pkgconf_pkg_t *parent;
+	pkgconf_pkg_t *match;
 };
 
 struct pkgconf_tuple_ {
@@ -128,7 +131,7 @@ struct pkgconf_pkg_ {
 	pkgconf_list_t cflags;
 	pkgconf_list_t cflags_private;
 
-        pkgconf_list_t requires_;        /* Keyword in C++20. */
+	pkgconf_list_t required;		/* this used to be requires but that is now a reserved keyword */
 	pkgconf_list_t requires_private;
 	pkgconf_list_t conflicts;
 	pkgconf_list_t provides;
@@ -136,6 +139,8 @@ struct pkgconf_pkg_ {
 	pkgconf_list_t vars;
 
 	unsigned int flags;
+
+	pkgconf_client_t *owner;
 };
 
 typedef bool (*pkgconf_pkg_iteration_func_t)(const pkgconf_pkg_t *pkg, void *data);
@@ -242,7 +247,7 @@ PKGCONF_API bool pkgconf_default_error_handler(const char *msg, const pkgconf_cl
 	} while (0);
 #endif
 
-PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg);
+PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_ref(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
 PKGCONF_API void pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
 PKGCONF_API void pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
 PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_find(pkgconf_client_t *client, const char *name);
@@ -272,6 +277,11 @@ PKGCONF_API int pkgconf_argv_split(const char *src, int *argc, char ***argv);
 PKGCONF_API void pkgconf_argv_free(char **argv);
 
 /* fragment.c */
+typedef struct pkgconf_fragment_render_ops_ {
+	size_t (*render_len)(const pkgconf_list_t *list, bool escape);
+	void (*render_buf)(const pkgconf_list_t *list, char *buf, size_t len, bool escape);
+} pkgconf_fragment_render_ops_t;
+
 typedef bool (*pkgconf_fragment_filter_func_t)(const pkgconf_client_t *client, const pkgconf_fragment_t *frag, void *data);
 PKGCONF_API bool pkgconf_fragment_parse(const pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_list_t *vars, const char *value);
 PKGCONF_API void pkgconf_fragment_add(const pkgconf_client_t *client, pkgconf_list_t *list, const char *string);
@@ -279,9 +289,9 @@ PKGCONF_API void pkgconf_fragment_copy(const pkgconf_client_t *client, pkgconf_l
 PKGCONF_API void pkgconf_fragment_delete(pkgconf_list_t *list, pkgconf_fragment_t *node);
 PKGCONF_API void pkgconf_fragment_free(pkgconf_list_t *list);
 PKGCONF_API void pkgconf_fragment_filter(const pkgconf_client_t *client, pkgconf_list_t *dest, pkgconf_list_t *src, pkgconf_fragment_filter_func_t filter_func, void *data);
-PKGCONF_API size_t pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape);
-PKGCONF_API void pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t len, bool escape);
-PKGCONF_API char *pkgconf_fragment_render(const pkgconf_list_t *list, bool escape);
+PKGCONF_API size_t pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops);
+PKGCONF_API void pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t len, bool escape, const pkgconf_fragment_render_ops_t *ops);
+PKGCONF_API char *pkgconf_fragment_render(const pkgconf_list_t *list, bool escape, const pkgconf_fragment_render_ops_t *ops);
 PKGCONF_API bool pkgconf_fragment_has_system_dir(const pkgconf_client_t *client, const pkgconf_fragment_t *frag);
 
 /* fileio.c */
@@ -306,7 +316,7 @@ PKGCONF_API bool pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *l
 PKGCONF_API bool pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth);
 
 /* cache.c */
-PKGCONF_API pkgconf_pkg_t *pkgconf_cache_lookup(const pkgconf_client_t *client, const char *id);
+PKGCONF_API pkgconf_pkg_t *pkgconf_cache_lookup(pkgconf_client_t *client, const char *id);
 PKGCONF_API void pkgconf_cache_add(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
 PKGCONF_API void pkgconf_cache_remove(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
 PKGCONF_API void pkgconf_cache_free(pkgconf_client_t *client);
diff --git a/libpkgconf/libpkgconf.h.orig b/libpkgconf/libpkgconf.h.orig
deleted file mode 100644
index ac873bf..0000000
--- a/libpkgconf/libpkgconf.h.orig
+++ /dev/null
@@ -1,331 +0,0 @@
-/*
- * libpkgconf.h
- * Global include file for everything in libpkgconf.
- *
- * Copyright (c) 2011, 2015 pkgconf authors (see AUTHORS).
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * This software is provided 'as is' and without any warranty, express or
- * implied.  In no event shall the authors be liable for any damages arising
- * from the use of this software.
- */
-
-#ifndef LIBPKGCONF__LIBPKGCONF_H
-#define LIBPKGCONF__LIBPKGCONF_H
-
-#include <stdio.h>
-#include <stdarg.h>
-#include <stddef.h>
-#include <stdbool.h>
-#include <libpkgconf/iter.h>
-#include <libpkgconf/bsdstubs.h>
-#include <libpkgconf/libpkgconf-api.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* pkg-config uses ';' on win32 as ':' is part of path */
-#ifdef _WIN32
-#define PKG_CONFIG_PATH_SEP_S   ";"
-#else
-#define PKG_CONFIG_PATH_SEP_S   ":"
-#endif
-
-#ifdef _WIN32
-#define PKG_DIR_SEP_S   '\\'
-#else
-#define PKG_DIR_SEP_S   '/'
-#endif
-
-#define PKGCONF_BUFSIZE	(65535)
-
-typedef enum {
-	PKGCONF_CMP_NOT_EQUAL,
-	PKGCONF_CMP_ANY,
-	PKGCONF_CMP_LESS_THAN,
-	PKGCONF_CMP_LESS_THAN_EQUAL,
-	PKGCONF_CMP_EQUAL,
-	PKGCONF_CMP_GREATER_THAN,
-	PKGCONF_CMP_GREATER_THAN_EQUAL
-} pkgconf_pkg_comparator_t;
-
-#define PKGCONF_CMP_COUNT 7
-
-typedef struct pkgconf_pkg_ pkgconf_pkg_t;
-typedef struct pkgconf_dependency_ pkgconf_dependency_t;
-typedef struct pkgconf_tuple_ pkgconf_tuple_t;
-typedef struct pkgconf_fragment_ pkgconf_fragment_t;
-typedef struct pkgconf_path_ pkgconf_path_t;
-typedef struct pkgconf_client_ pkgconf_client_t;
-
-#define PKGCONF_ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
-
-#define PKGCONF_FOREACH_LIST_ENTRY(head, value) \
-	for ((value) = (head); (value) != NULL; (value) = (value)->next)
-
-#define PKGCONF_FOREACH_LIST_ENTRY_SAFE(head, nextiter, value) \
-	for ((value) = (head), (nextiter) = (head) != NULL ? (head)->next : NULL; (value) != NULL; (value) = (nextiter), (nextiter) = (nextiter) != NULL ? (nextiter)->next : NULL)
-
-#define PKGCONF_FOREACH_LIST_ENTRY_REVERSE(tail, value) \
-	for ((value) = (tail); (value) != NULL; (value) = (value)->prev)
-
-struct pkgconf_fragment_ {
-	pkgconf_node_t iter;
-
-	char type;
-	char *data;
-};
-
-struct pkgconf_dependency_ {
-	pkgconf_node_t iter;
-
-	char *package;
-	pkgconf_pkg_comparator_t compare;
-	char *version;
-	pkgconf_pkg_t *parent;
-};
-
-struct pkgconf_tuple_ {
-	pkgconf_node_t iter;
-
-	char *key;
-	char *value;
-};
-
-struct pkgconf_path_ {
-	pkgconf_node_t lnode;
-
-	char *path;
-	void *handle_path;
-	void *handle_device;
-};
-
-#define PKGCONF_PKG_PROPF_NONE			0x00
-#define PKGCONF_PKG_PROPF_STATIC		0x01
-#define PKGCONF_PKG_PROPF_CACHED		0x02
-#define PKGCONF_PKG_PROPF_SEEN			0x04
-#define PKGCONF_PKG_PROPF_UNINSTALLED		0x08
-#define PKGCONF_PKG_PROPF_VIRTUAL		0x10
-
-struct pkgconf_pkg_ {
-	pkgconf_node_t cache_iter;
-
-	int refcount;
-	char *id;
-	char *filename;
-	char *realname;
-	char *version;
-	char *description;
-	char *url;
-	char *pc_filedir;
-
-	pkgconf_list_t libs;
-	pkgconf_list_t libs_private;
-	pkgconf_list_t cflags;
-	pkgconf_list_t cflags_private;
-
-	pkgconf_list_t requires;
-	pkgconf_list_t requires_private;
-	pkgconf_list_t conflicts;
-	pkgconf_list_t provides;
-
-	pkgconf_list_t vars;
-
-	unsigned int flags;
-};
-
-typedef bool (*pkgconf_pkg_iteration_func_t)(const pkgconf_pkg_t *pkg, void *data);
-typedef void (*pkgconf_pkg_traverse_func_t)(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data);
-typedef bool (*pkgconf_queue_apply_func_t)(pkgconf_client_t *client, pkgconf_pkg_t *world, void *data, int maxdepth);
-typedef bool (*pkgconf_error_handler_func_t)(const char *msg, const pkgconf_client_t *client, const void *data);
-
-struct pkgconf_client_ {
-	pkgconf_list_t dir_list;
-	pkgconf_list_t pkg_cache;
-
-	pkgconf_list_t filter_libdirs;
-	pkgconf_list_t filter_includedirs;
-
-	pkgconf_list_t global_vars;
-
-	void *error_handler_data;
-	void *warn_handler_data;
-	void *trace_handler_data;
-
-	pkgconf_error_handler_func_t error_handler;
-	pkgconf_error_handler_func_t warn_handler;
-	pkgconf_error_handler_func_t trace_handler;
-
-	FILE *auditf;
-
-	char *sysroot_dir;
-	char *buildroot_dir;
-
-	unsigned int flags;
-
-	char *prefix_varname;
-
-	bool already_sent_notice;
-};
-
-/* client.c */
-PKGCONF_API void pkgconf_client_init(pkgconf_client_t *client, pkgconf_error_handler_func_t error_handler, void *error_handler_data);
-PKGCONF_API pkgconf_client_t * pkgconf_client_new(pkgconf_error_handler_func_t error_handler, void *error_handler_data);
-PKGCONF_API void pkgconf_client_deinit(pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_free(pkgconf_client_t *client);
-PKGCONF_API const char *pkgconf_client_get_sysroot_dir(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_sysroot_dir(pkgconf_client_t *client, const char *sysroot_dir);
-PKGCONF_API const char *pkgconf_client_get_buildroot_dir(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_buildroot_dir(pkgconf_client_t *client, const char *buildroot_dir);
-PKGCONF_API unsigned int pkgconf_client_get_flags(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_flags(pkgconf_client_t *client, unsigned int flags);
-PKGCONF_API const char *pkgconf_client_get_prefix_varname(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_prefix_varname(pkgconf_client_t *client, const char *prefix_varname);
-PKGCONF_API pkgconf_error_handler_func_t pkgconf_client_get_warn_handler(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_warn_handler(pkgconf_client_t *client, pkgconf_error_handler_func_t warn_handler, void *warn_handler_data);
-PKGCONF_API pkgconf_error_handler_func_t pkgconf_client_get_error_handler(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_error_handler(pkgconf_client_t *client, pkgconf_error_handler_func_t error_handler, void *error_handler_data);
-PKGCONF_API pkgconf_error_handler_func_t pkgconf_client_get_trace_handler(const pkgconf_client_t *client);
-PKGCONF_API void pkgconf_client_set_trace_handler(pkgconf_client_t *client, pkgconf_error_handler_func_t trace_handler, void *trace_handler_data);
-
-#define PKGCONF_IS_MODULE_SEPARATOR(c) ((c) == ',' || isspace ((unsigned int)(c)))
-#define PKGCONF_IS_OPERATOR_CHAR(c) ((c) == '<' || (c) == '>' || (c) == '!' || (c) == '=')
-
-#define PKGCONF_PKG_PKGF_NONE				0x0000
-#define PKGCONF_PKG_PKGF_SEARCH_PRIVATE			0x0001
-#define PKGCONF_PKG_PKGF_ENV_ONLY			0x0002
-#define PKGCONF_PKG_PKGF_NO_UNINSTALLED			0x0004
-#define PKGCONF_PKG_PKGF_SKIP_ROOT_VIRTUAL		0x0008
-#define PKGCONF_PKG_PKGF_MERGE_PRIVATE_FRAGMENTS	0x0010
-#define PKGCONF_PKG_PKGF_SKIP_CONFLICTS			0x0020
-#define PKGCONF_PKG_PKGF_NO_CACHE			0x0040
-#define PKGCONF_PKG_PKGF_SKIP_ERRORS			0x0080
-#define PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE		0x0100
-#define PKGCONF_PKG_PKGF_SKIP_PROVIDES			0x0200
-#define PKGCONF_PKG_PKGF_REDEFINE_PREFIX		0x0400
-#define PKGCONF_PKG_PKGF_DONT_RELOCATE_PATHS		0x0800
-#define PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS		0x1000
-
-#define PKGCONF_PKG_ERRF_OK			0x0
-#define PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND	0x1
-#define PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH	0x2
-#define PKGCONF_PKG_ERRF_PACKAGE_CONFLICT	0x4
-#define PKGCONF_PKG_ERRF_DEPGRAPH_BREAK		0x8
-
-/* pkg.c */
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#define PRINTFLIKE(fmtarg, firstvararg) \
-        __attribute__((__format__ (__printf__, fmtarg, firstvararg)))
-#define DEPRECATED \
-        __attribute__((deprecated))
-#else
-#define PRINTFLIKE(fmtarg, firstvararg)
-#define DEPRECATED
-#endif /* defined(__INTEL_COMPILER) || defined(__GNUC__) */
-
-PKGCONF_API bool pkgconf_error(const pkgconf_client_t *client, const char *format, ...) PRINTFLIKE(2, 3);
-PKGCONF_API bool pkgconf_warn(const pkgconf_client_t *client, const char *format, ...) PRINTFLIKE(2, 3);
-PKGCONF_API bool pkgconf_trace(const pkgconf_client_t *client, const char *filename, size_t lineno, const char *funcname, const char *format, ...) PRINTFLIKE(5, 6);
-PKGCONF_API bool pkgconf_default_error_handler(const char *msg, const pkgconf_client_t *client, const void *data);
-
-#if defined(__GNUC__) || defined(__INTEL_COMPILER)
-#define PKGCONF_TRACE(client, ...) do { \
-		pkgconf_trace(client, __FILE__, __LINE__, __PRETTY_FUNCTION__, __VA_ARGS__); \
-	} while (0);
-#else
-#define PKGCONF_TRACE(client, ...) do { \
-		pkgconf_trace(client, __FILE__, __LINE__, __func__, __VA_ARGS__); \
-	} while (0);
-#endif
-
-PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg);
-PKGCONF_API void pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
-PKGCONF_API void pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
-PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_find(pkgconf_client_t *client, const char *name);
-PKGCONF_API unsigned int pkgconf_pkg_traverse(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_pkg_traverse_func_t func, void *data, int maxdepth);
-PKGCONF_API unsigned int pkgconf_pkg_verify_graph(pkgconf_client_t *client, pkgconf_pkg_t *root, int depth);
-PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int *eflags);
-PKGCONF_API const char *pkgconf_pkg_get_comparator(const pkgconf_dependency_t *pkgdep);
-PKGCONF_API unsigned int pkgconf_pkg_cflags(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth);
-PKGCONF_API unsigned int pkgconf_pkg_libs(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth);
-PKGCONF_API pkgconf_pkg_comparator_t pkgconf_pkg_comparator_lookup_by_name(const char *name);
-PKGCONF_API pkgconf_pkg_t *pkgconf_builtin_pkg_get(const char *name);
-
-PKGCONF_API int pkgconf_compare_version(const char *a, const char *b);
-PKGCONF_API pkgconf_pkg_t *pkgconf_scan_all(pkgconf_client_t *client, void *ptr, pkgconf_pkg_iteration_func_t func);
-PKGCONF_API void pkgconf_pkg_dir_list_build(pkgconf_client_t *client);
-
-/* parse.c */
-PKGCONF_API pkgconf_pkg_t *pkgconf_pkg_new_from_file(pkgconf_client_t *client, const char *path, FILE *f);
-PKGCONF_API void pkgconf_dependency_parse_str(const pkgconf_client_t *client, pkgconf_list_t *deplist_head, const char *depends);
-PKGCONF_API void pkgconf_dependency_parse(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, pkgconf_list_t *deplist_head, const char *depends);
-PKGCONF_API void pkgconf_dependency_append(pkgconf_list_t *list, pkgconf_dependency_t *tail);
-PKGCONF_API void pkgconf_dependency_free(pkgconf_list_t *list);
-PKGCONF_API pkgconf_dependency_t *pkgconf_dependency_add(const pkgconf_client_t *client, pkgconf_list_t *list, const char *package, const char *version, pkgconf_pkg_comparator_t compare);
-
-/* argvsplit.c */
-PKGCONF_API int pkgconf_argv_split(const char *src, int *argc, char ***argv);
-PKGCONF_API void pkgconf_argv_free(char **argv);
-
-/* fragment.c */
-typedef bool (*pkgconf_fragment_filter_func_t)(const pkgconf_client_t *client, const pkgconf_fragment_t *frag, void *data);
-PKGCONF_API bool pkgconf_fragment_parse(const pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_list_t *vars, const char *value);
-PKGCONF_API void pkgconf_fragment_add(const pkgconf_client_t *client, pkgconf_list_t *list, const char *string);
-PKGCONF_API void pkgconf_fragment_copy(const pkgconf_client_t *client, pkgconf_list_t *list, const pkgconf_fragment_t *base, bool is_private);
-PKGCONF_API void pkgconf_fragment_delete(pkgconf_list_t *list, pkgconf_fragment_t *node);
-PKGCONF_API void pkgconf_fragment_free(pkgconf_list_t *list);
-PKGCONF_API void pkgconf_fragment_filter(const pkgconf_client_t *client, pkgconf_list_t *dest, pkgconf_list_t *src, pkgconf_fragment_filter_func_t filter_func, void *data);
-PKGCONF_API size_t pkgconf_fragment_render_len(const pkgconf_list_t *list, bool escape);
-PKGCONF_API void pkgconf_fragment_render_buf(const pkgconf_list_t *list, char *buf, size_t len, bool escape);
-PKGCONF_API char *pkgconf_fragment_render(const pkgconf_list_t *list, bool escape);
-PKGCONF_API bool pkgconf_fragment_has_system_dir(const pkgconf_client_t *client, const pkgconf_fragment_t *frag);
-
-/* fileio.c */
-PKGCONF_API char *pkgconf_fgetline(char *line, size_t size, FILE *stream);
-
-/* tuple.c */
-PKGCONF_API pkgconf_tuple_t *pkgconf_tuple_add(const pkgconf_client_t *client, pkgconf_list_t *parent, const char *key, const char *value, bool parse);
-PKGCONF_API char *pkgconf_tuple_find(const pkgconf_client_t *client, pkgconf_list_t *list, const char *key);
-PKGCONF_API char *pkgconf_tuple_parse(const pkgconf_client_t *client, pkgconf_list_t *list, const char *value);
-PKGCONF_API void pkgconf_tuple_free(pkgconf_list_t *list);
-PKGCONF_API void pkgconf_tuple_free_entry(pkgconf_tuple_t *tuple, pkgconf_list_t *list);
-PKGCONF_API void pkgconf_tuple_add_global(pkgconf_client_t *client, const char *key, const char *value);
-PKGCONF_API char *pkgconf_tuple_find_global(const pkgconf_client_t *client, const char *key);
-PKGCONF_API void pkgconf_tuple_free_global(pkgconf_client_t *client);
-PKGCONF_API void pkgconf_tuple_define_global(pkgconf_client_t *client, const char *kv);
-
-/* queue.c */
-PKGCONF_API void pkgconf_queue_push(pkgconf_list_t *list, const char *package);
-PKGCONF_API bool pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list);
-PKGCONF_API void pkgconf_queue_free(pkgconf_list_t *list);
-PKGCONF_API bool pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data);
-PKGCONF_API bool pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth);
-
-/* cache.c */
-PKGCONF_API pkgconf_pkg_t *pkgconf_cache_lookup(const pkgconf_client_t *client, const char *id);
-PKGCONF_API void pkgconf_cache_add(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
-PKGCONF_API void pkgconf_cache_remove(pkgconf_client_t *client, pkgconf_pkg_t *pkg);
-PKGCONF_API void pkgconf_cache_free(pkgconf_client_t *client);
-
-/* audit.c */
-PKGCONF_API void pkgconf_audit_set_log(pkgconf_client_t *client, FILE *auditf);
-PKGCONF_API void pkgconf_audit_log(pkgconf_client_t *client, const char *format, ...) PRINTFLIKE(2, 3);
-PKGCONF_API void pkgconf_audit_log_dependency(pkgconf_client_t *client, const pkgconf_pkg_t *dep, const pkgconf_dependency_t *depnode);
-
-/* path.c */
-PKGCONF_API void pkgconf_path_add(const char *text, pkgconf_list_t *dirlist, bool filter);
-PKGCONF_API size_t pkgconf_path_split(const char *text, pkgconf_list_t *dirlist, bool filter);
-PKGCONF_API size_t pkgconf_path_build_from_environ(const char *envvarname, const char *fallback, pkgconf_list_t *dirlist, bool filter);
-PKGCONF_API bool pkgconf_path_match_list(const char *path, const pkgconf_list_t *dirlist);
-PKGCONF_API void pkgconf_path_free(pkgconf_list_t *dirlist);
-PKGCONF_API bool pkgconf_path_relocate(char *buf, size_t buflen);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/libpkgconf/pkg.c b/libpkgconf/pkg.c
index 3e3268a..6918d6d 100644
--- a/libpkgconf/pkg.c
+++ b/libpkgconf/pkg.c
@@ -181,7 +181,7 @@ static const pkgconf_pkg_parser_keyword_pair_t pkgconf_pkg_parser_keyword_funcs[
 	{"LIBS.private", pkgconf_pkg_parser_fragment_func, offsetof(pkgconf_pkg_t, libs_private)},
 	{"Name", pkgconf_pkg_parser_tuple_func, offsetof(pkgconf_pkg_t, realname)},
 	{"Provides", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, provides)},
-	{"Requires", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, requires_)},
+	{"Requires", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, required)},
 	{"Requires.private", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, requires_private)},
 	{"Version", pkgconf_pkg_parser_tuple_func, offsetof(pkgconf_pkg_t, version)},
 };
@@ -423,7 +423,7 @@ pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 
 	pkgconf_cache_remove(client, pkg);
 
-	pkgconf_dependency_free(&pkg->requires_);
+	pkgconf_dependency_free(&pkg->required);
 	pkgconf_dependency_free(&pkg->requires_private);
 	pkgconf_dependency_free(&pkg->conflicts);
 	pkgconf_dependency_free(&pkg->provides);
@@ -475,11 +475,15 @@ pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
  *    :rtype: pkgconf_pkg_t *
  */
 pkgconf_pkg_t *
-pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg)
+pkgconf_pkg_ref(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
-	(void) client;
+	if (pkg->owner != NULL && pkg->owner != client)
+		PKGCONF_TRACE(client, "WTF: client %p refers to package %p owned by other client %p", client, pkg, pkg->owner);
 
+	pkg->owner = client;
 	pkg->refcount++;
+	PKGCONF_TRACE(client, "refcount@%p: %d", pkg, pkg->refcount);
+
 	return pkg;
 }
 
@@ -497,9 +501,14 @@ pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 void
 pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
 {
+	if (pkg->owner != NULL && pkg->owner != client)
+		PKGCONF_TRACE(client, "WTF: client %p unrefs package %p owned by other client %p", client, pkg, pkg->owner);
+
 	pkg->refcount--;
+	PKGCONF_TRACE(pkg->owner, "refcount@%p: %d", pkg, pkg->refcount);
+
 	if (pkg->refcount <= 0)
-		pkgconf_pkg_free(client, pkg);
+		pkgconf_pkg_free(pkg->owner, pkg);
 }
 
 static inline pkgconf_pkg_t *
@@ -1264,6 +1273,12 @@ pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pk
 
 	PKGCONF_TRACE(client, "trying to verify dependency: %s", pkgdep->package);
 
+	if (pkgdep->match != NULL)
+	{
+		PKGCONF_TRACE(client, "cached dependency: %s -> %s@%p", pkgdep->package, pkgdep->match->id, pkgdep->match);
+		return pkgconf_pkg_ref(client, pkgdep->match);
+	}
+
 	pkg = pkgconf_pkg_find(client, pkgdep->package);
 	if (pkg == NULL)
 	{
@@ -1281,11 +1296,13 @@ pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pk
 	if (pkg->id == NULL)
 		pkg->id = strdup(pkgdep->package);
 
-	if (pkgconf_pkg_comparator_impls[pkgdep->compare](pkg->version, pkgdep->version) == true)
-		return pkg;
-
-	if (eflags != NULL)
-		*eflags |= PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH;
+	if (pkgconf_pkg_comparator_impls[pkgdep->compare](pkg->version, pkgdep->version) != true)
+	{
+		if (eflags != NULL)
+			*eflags |= PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH;
+	}
+	else
+		pkgdep->match = pkgconf_pkg_ref(client, pkg);
 
 	return pkg;
 }
@@ -1331,11 +1348,7 @@ pkgconf_pkg_report_graph_error(pkgconf_client_t *client, pkgconf_pkg_t *parent,
 		pkgconf_error(client, "Package dependency requirement '%s %s %s' could not be satisfied.\n",
 			node->package, pkgconf_pkg_get_comparator(node), node->version);
 
-    /*
-     * Add support for PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS flag (issue #134 is
-     * reported).
-     */
-		if (pkg != NULL && !(client->flags & PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS))
+		if (pkg != NULL)
 			pkgconf_error(client, "Package '%s' has version '%s', required version is '%s %s'\n",
 				node->package, pkg->version, pkgconf_pkg_get_comparator(node), node->version);
 	}
@@ -1408,7 +1421,7 @@ pkgconf_pkg_walk_conflicts_list(pkgconf_client_t *client,
 		if (*parentnode->package == '\0')
 			continue;
 
-		PKGCONF_FOREACH_LIST_ENTRY(root->requires_.head, childnode)
+		PKGCONF_FOREACH_LIST_ENTRY(root->required.head, childnode)
 		{
 			pkgconf_pkg_t *pkgdep;
 			pkgconf_dependency_t *depnode = childnode->data;
@@ -1423,15 +1436,11 @@ pkgconf_pkg_walk_conflicts_list(pkgconf_client_t *client,
 					pkgdep->version, pkgdep->realname, root->realname, parentnode->package, pkgconf_pkg_get_comparator(parentnode),
 					parentnode->version != NULL ? " " : "", parentnode->version != NULL ? parentnode->version : "");
 
-        /*
-         * Add support for PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS flag (issue #134 is
-         * reported).
-         */
-        if (!(client->flags & PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS))
-        {
+				if (!(client->flags & PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS))
+				{
 					pkgconf_error(client, "It may be possible to ignore this conflict and continue, try the\n");
 					pkgconf_error(client, "PKG_CONFIG_IGNORE_CONFLICTS environment variable.\n");
-        }
+				}
 
 				pkgconf_pkg_unref(client, pkgdep);
 
@@ -1488,7 +1497,7 @@ pkgconf_pkg_traverse(pkgconf_client_t *client,
 	}
 
 	PKGCONF_TRACE(client, "%s: walking requires list", root->id);
-	eflags = pkgconf_pkg_walk_list(client, root, &root->requires_, func, data, maxdepth);
+	eflags = pkgconf_pkg_walk_list(client, root, &root->required, func, data, maxdepth);
 	if (eflags != PKGCONF_PKG_ERRF_OK)
 		return eflags;
 
diff --git a/libpkgconf/pkg.c.orig b/libpkgconf/pkg.c.orig
deleted file mode 100644
index ea970b8..0000000
--- a/libpkgconf/pkg.c.orig
+++ /dev/null
@@ -1,1608 +0,0 @@
-/*
- * pkg.c
- * higher-level dependency graph compilation, management and manipulation
- *
- * Copyright (c) 2011, 2012, 2013 pkgconf authors (see AUTHORS).
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * This software is provided 'as is' and without any warranty, express or
- * implied.  In no event shall the authors be liable for any damages arising
- * from the use of this software.
- */
-
-#include <libpkgconf/stdinc.h>
-#include <libpkgconf/config.h>
-#include <libpkgconf/libpkgconf.h>
-
-/*
- * !doc
- *
- * libpkgconf `pkg` module
- * =======================
- *
- * The `pkg` module provides dependency resolution services and the overall `.pc` file parsing
- * routines.
- */
-
-#ifdef _WIN32
-#	define PKG_CONFIG_REG_KEY "Software\\pkgconfig\\PKG_CONFIG_PATH"
-#	undef PKG_DEFAULT_PATH
-#	define PKG_DEFAULT_PATH "../lib/pkgconfig;../share/pkgconfig"
-#	define strncasecmp _strnicmp
-#	define strcasecmp _stricmp
-#endif
-
-#define PKG_CONFIG_EXT ".pc"
-
-static inline bool
-str_has_suffix(const char *str, const char *suffix)
-{
-	size_t str_len = strlen(str);
-	size_t suf_len = strlen(suffix);
-
-	if (str_len < suf_len)
-		return false;
-
-	return !strncasecmp(str + str_len - suf_len, suffix, suf_len);
-}
-
-static inline const char *
-get_default_pkgconfig_path(char *outbuf, size_t outlen)
-{
-#ifdef _WIN32
-	char namebuf[MAX_PATH];
-	char *p;
-
-	int sizepath = GetModuleFileName(NULL, namebuf, sizeof namebuf);
-	char * winslash;
-	namebuf[sizepath] = '\0';
-	while ((winslash = strchr (namebuf, '\\')) != NULL)
-	{
-		*winslash = '/';
-	}
-	p = strrchr(namebuf, '/');
-	if (p == NULL)
-		return PKG_DEFAULT_PATH;
-
-	*p = '\0';
-	pkgconf_strlcpy(outbuf, namebuf, outlen);
-	pkgconf_strlcat(outbuf, "/", outlen);
-	pkgconf_strlcat(outbuf, "../lib/pkgconfig", outlen);
-	pkgconf_strlcat(outbuf, ";", outlen);
-	pkgconf_strlcat(outbuf, namebuf, outlen);
-	pkgconf_strlcat(outbuf, "/", outlen);
-	pkgconf_strlcat(outbuf, "../share/pkgconfig", outlen);
-
-	return outbuf;
-#else
-	(void) outbuf;
-	(void) outlen;
-#endif
-
-	return PKG_DEFAULT_PATH;
-}
-
-static const char *
-pkg_get_parent_dir(pkgconf_pkg_t *pkg, char *buf, size_t buflen)
-{
-	char *pathbuf;
-
-	pkgconf_strlcpy(buf, pkg->filename, buflen);
-	pathbuf = strrchr(buf, PKG_DIR_SEP_S);
-	if (pathbuf == NULL)
-		pathbuf = strrchr(buf, '/');
-	if (pathbuf != NULL)
-		pathbuf[0] = '\0';
-
-	return buf;
-}
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_pkg_dir_list_build(pkgconf_client_t *client)
- *
- *    Bootstraps the package search paths.  If the ``PKGCONF_PKG_PKGF_ENV_ONLY`` `flag` is set on the client,
- *    then only the ``PKG_CONFIG_PATH`` environment variable will be used, otherwise both the
- *    ``PKG_CONFIG_PATH`` and ``PKG_CONFIG_LIBDIR`` environment variables will be used.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to bootstrap.
- *    :return: nothing
- */
-void
-pkgconf_pkg_dir_list_build(pkgconf_client_t *client)
-{
-	pkgconf_path_build_from_environ("PKG_CONFIG_PATH", NULL, &client->dir_list, true);
-
-	if (!(client->flags & PKGCONF_PKG_PKGF_ENV_ONLY))
-	{
-		char pathbuf[PKGCONF_BUFSIZE];
-
-		pkgconf_path_build_from_environ("PKG_CONFIG_LIBDIR", get_default_pkgconfig_path(pathbuf, sizeof pathbuf), &client->dir_list, true);
-	}
-}
-
-typedef void (*pkgconf_pkg_parser_keyword_func_t)(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, const char *keyword, const size_t lineno, const ptrdiff_t offset, char *value);
-typedef struct {
-	const char *keyword;
-	const pkgconf_pkg_parser_keyword_func_t func;
-	const ptrdiff_t offset;
-} pkgconf_pkg_parser_keyword_pair_t;
-
-static int pkgconf_pkg_parser_keyword_pair_cmp(const void *key, const void *ptr)
-{
-	const pkgconf_pkg_parser_keyword_pair_t *pair = ptr;
-	return strcasecmp(key, pair->keyword);
-}
-
-static void
-pkgconf_pkg_parser_tuple_func(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, const char *keyword, const size_t lineno, const ptrdiff_t offset, char *value)
-{
-	(void) keyword;
-	(void) lineno;
-
-	char **dest = (char **)((char *) pkg + offset);
-	*dest = pkgconf_tuple_parse(client, &pkg->vars, value);
-}
-
-static void
-pkgconf_pkg_parser_fragment_func(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, const char *keyword, const size_t lineno, const ptrdiff_t offset, char *value)
-{
-	pkgconf_list_t *dest = (pkgconf_list_t *)((char *) pkg + offset);
-	bool ret = pkgconf_fragment_parse(client, dest, &pkg->vars, value);
-
-	if (!ret)
-	{
-		pkgconf_warn(client, "%s:" SIZE_FMT_SPECIFIER ": warning: unable to parse field '%s' into an argument vector, value [%s]\n", pkg->filename,
-			     lineno, keyword, value);
-	}
-}
-
-static void
-pkgconf_pkg_parser_dependency_func(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, const char *keyword, const size_t lineno, const ptrdiff_t offset, char *value)
-{
-	(void) keyword;
-	(void) lineno;
-
-	pkgconf_list_t *dest = (pkgconf_list_t *)((char *) pkg + offset);
-	pkgconf_dependency_parse(client, pkg, dest, value);
-}
-
-/* keep this in alphabetical order */
-static const pkgconf_pkg_parser_keyword_pair_t pkgconf_pkg_parser_keyword_funcs[] = {
-	{"CFLAGS", pkgconf_pkg_parser_fragment_func, offsetof(pkgconf_pkg_t, cflags)},
-	{"CFLAGS.private", pkgconf_pkg_parser_fragment_func, offsetof(pkgconf_pkg_t, cflags_private)},
-	{"Conflicts", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, conflicts)},
-	{"Description", pkgconf_pkg_parser_tuple_func, offsetof(pkgconf_pkg_t, description)},
-	{"LIBS", pkgconf_pkg_parser_fragment_func, offsetof(pkgconf_pkg_t, libs)},
-	{"LIBS.private", pkgconf_pkg_parser_fragment_func, offsetof(pkgconf_pkg_t, libs_private)},
-	{"Name", pkgconf_pkg_parser_tuple_func, offsetof(pkgconf_pkg_t, realname)},
-	{"Provides", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, provides)},
-	{"Requires", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, requires)},
-	{"Requires.private", pkgconf_pkg_parser_dependency_func, offsetof(pkgconf_pkg_t, requires_private)},
-	{"Version", pkgconf_pkg_parser_tuple_func, offsetof(pkgconf_pkg_t, version)},
-};
-
-static bool
-pkgconf_pkg_parser_keyword_set(const pkgconf_client_t *client, pkgconf_pkg_t *pkg, const size_t lineno, const char *keyword, char *value)
-{
-	const pkgconf_pkg_parser_keyword_pair_t *pair = bsearch(keyword,
-		pkgconf_pkg_parser_keyword_funcs, PKGCONF_ARRAY_SIZE(pkgconf_pkg_parser_keyword_funcs),
-		sizeof(pkgconf_pkg_parser_keyword_pair_t), pkgconf_pkg_parser_keyword_pair_cmp);
-
-	if (pair == NULL || pair->func == NULL)
-		return false;
-
-	pair->func(client, pkg, keyword, lineno, pair->offset, value);
-	return true;
-}
-
-static const char *
-determine_prefix(const pkgconf_pkg_t *pkg, char *buf, size_t buflen)
-{
-	char *pathiter;
-
-	pkgconf_strlcpy(buf, pkg->filename, buflen);
-	pkgconf_path_relocate(buf, buflen);
-
-	pathiter = strrchr(buf, PKG_DIR_SEP_S);
-	if (pathiter == NULL)
-		pathiter = strrchr(buf, '/');
-	if (pathiter != NULL)
-		pathiter[0] = '\0';
-
-	pathiter = strrchr(buf, PKG_DIR_SEP_S);
-	if (pathiter == NULL)
-		pathiter = strrchr(buf, '/');
-	if (pathiter == NULL)
-		return NULL;
-
-	/* parent dir is not pkgconfig, can't relocate then */
-	if (strcmp(pathiter + 1, "pkgconfig"))
-		return NULL;
-
-	/* okay, work backwards and do it again. */
-	pathiter[0] = '\0';
-	pathiter = strrchr(buf, PKG_DIR_SEP_S);
-	if (pathiter == NULL)
-		pathiter = strrchr(buf, '/');
-	if (pathiter == NULL)
-		return NULL;
-
-	pathiter[0] = '\0';
-
-	return buf;
-}
-
-typedef struct {
-	const char *field;
-	const ptrdiff_t offset;
-} pkgconf_pkg_validity_check_t;
-
-static const pkgconf_pkg_validity_check_t pkgconf_pkg_validations[] = {
-	{"Name", offsetof(pkgconf_pkg_t, realname)},
-	{"Description", offsetof(pkgconf_pkg_t, description)},
-	{"Version", offsetof(pkgconf_pkg_t, version)},
-};
-
-static bool
-pkgconf_pkg_validate(const pkgconf_client_t *client, const pkgconf_pkg_t *pkg)
-{
-	size_t i;
-	bool valid = true;
-
-	for (i = 0; i < PKGCONF_ARRAY_SIZE(pkgconf_pkg_validations); i++)
-	{
-		char **p = (char **)((char *) pkg + pkgconf_pkg_validations[i].offset);
-
-		if (*p != NULL)
-			continue;
-
-		pkgconf_warn(client, "%s: warning: file does not declare a `%s' field\n", pkg->filename, pkgconf_pkg_validations[i].field);
-		valid = false;
-	}
-
-	return valid;
-}
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_t *pkgconf_pkg_new_from_file(const pkgconf_client_t *client, const char *filename, FILE *f)
- *
- *    Parse a .pc file into a pkgconf_pkg_t object structure.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param char* filename: The filename of the package file (including full path).
- *    :param FILE* f: The file object to read from.
- *    :returns: A ``pkgconf_pkg_t`` object which contains the package data.
- *    :rtype: pkgconf_pkg_t *
- */
-pkgconf_pkg_t *
-pkgconf_pkg_new_from_file(pkgconf_client_t *client, const char *filename, FILE *f)
-{
-	pkgconf_pkg_t *pkg;
-	char readbuf[PKGCONF_BUFSIZE];
-	char pathbuf[PKGCONF_ITEM_SIZE];
-	char *idptr;
-	size_t lineno = 0;
-
-	pkg = calloc(sizeof(pkgconf_pkg_t), 1);
-	pkg->filename = strdup(filename);
-	pkgconf_tuple_add(client, &pkg->vars, "pcfiledir", pkg_get_parent_dir(pkg, pathbuf, sizeof pathbuf), true);
-
-	/* make module id */
-	if ((idptr = strrchr(pkg->filename, PKG_DIR_SEP_S)) != NULL)
-		idptr++;
-#ifdef _WIN32
-	else if ((idptr = strrchr(pkg->filename, '/')) != NULL)
-		idptr++;
-#endif
-	else
-		idptr = pkg->filename;
-
-	pkg->id = strdup(idptr);
-	idptr = strrchr(pkg->id, '.');
-	if (idptr)
-		*idptr = '\0';
-
-	while (pkgconf_fgetline(readbuf, PKGCONF_BUFSIZE, f) != NULL)
-	{
-		char op, *p, *key, *value;
-		bool warned_key_whitespace = false, warned_value_whitespace = false;
-
-		lineno++;
-
-		PKGCONF_TRACE(client, "%s:" SIZE_FMT_SPECIFIER " > [%s]", filename, lineno, readbuf);
-
-		p = readbuf;
-		while (*p && (isalpha((unsigned int)*p) || isdigit((unsigned int)*p) || *p == '_' || *p == '.'))
-			p++;
-
-		key = readbuf;
-		if (!isalpha((unsigned int)*key) && !isdigit((unsigned int)*p))
-			continue;
-
-		while (*p && isspace((unsigned int)*p))
-		{
-			if (!warned_key_whitespace)
-			{
-				pkgconf_warn(client, "%s:" SIZE_FMT_SPECIFIER ": warning: whitespace encountered while parsing key section\n",
-					pkg->filename, lineno);
-				warned_key_whitespace = true;
-			}
-
-			/* set to null to avoid trailing spaces in key */
-			*p = '\0';
-			p++;
-		}
-
-		op = *p;
-		*p = '\0';
-		p++;
-
-		while (*p && isspace((unsigned int)*p))
-			p++;
-
-		value = p;
-		p = value + (strlen(value) - 1);
-		while (*p && isspace((unsigned int) *p) && p > value)
-		{
-			if (!warned_value_whitespace && op == '=')
-			{
-				pkgconf_warn(client, "%s:" SIZE_FMT_SPECIFIER ": warning: trailing whitespace encountered while parsing value section\n",
-					pkg->filename, lineno);
-				warned_value_whitespace = true;
-			}
-
-			*p = '\0';
-			p--;
-		}
-
-		switch (op)
-		{
-		case ':':
-			pkgconf_pkg_parser_keyword_set(client, pkg, lineno, key, value);
-			break;
-		case '=':
-			if (strcmp(key, client->prefix_varname) || !(client->flags & PKGCONF_PKG_PKGF_REDEFINE_PREFIX))
-				pkgconf_tuple_add(client, &pkg->vars, key, value, true);
-			else
-			{
-				const char *relvalue = determine_prefix(pkg, pathbuf, sizeof pathbuf);
-				if (relvalue != NULL)
-				{
-					pkgconf_tuple_add(client, &pkg->vars, "orig_prefix", value, true);
-					pkgconf_tuple_add(client, &pkg->vars, key, relvalue, false);
-				}
-				else
-					pkgconf_tuple_add(client, &pkg->vars, key, value, true);
-			}
-			break;
-		default:
-			break;
-		}
-	}
-
-	fclose(f);
-
-	if (!pkgconf_pkg_validate(client, pkg))
-	{
-		pkgconf_warn(client, "%s: warning: skipping invalid file\n", pkg->filename);
-		pkgconf_pkg_free(client, pkg);
-		return NULL;
-	}
-
-	pkgconf_dependency_add(client, &pkg->provides, pkg->id, pkg->version, PKGCONF_CMP_EQUAL);
-
-	return pkgconf_pkg_ref(client, pkg);
-}
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
- *
- *    Releases all releases for a given ``pkgconf_pkg_t`` object.
- *
- *    :param pkgconf_client_t* client: The client which owns the ``pkgconf_pkg_t`` object, `pkg`.
- *    :param pkgconf_pkg_t* pkg: The package to free.
- *    :return: nothing
- */
-void
-pkgconf_pkg_free(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
-{
-	if (pkg == NULL)
-		return;
-
-	if (pkg->flags & PKGCONF_PKG_PROPF_STATIC && !(pkg->flags & PKGCONF_PKG_PROPF_VIRTUAL))
-		return;
-
-	pkgconf_cache_remove(client, pkg);
-
-	pkgconf_dependency_free(&pkg->requires);
-	pkgconf_dependency_free(&pkg->requires_private);
-	pkgconf_dependency_free(&pkg->conflicts);
-	pkgconf_dependency_free(&pkg->provides);
-
-	pkgconf_fragment_free(&pkg->cflags);
-	pkgconf_fragment_free(&pkg->cflags_private);
-	pkgconf_fragment_free(&pkg->libs);
-	pkgconf_fragment_free(&pkg->libs_private);
-
-	pkgconf_tuple_free(&pkg->vars);
-
-	if (pkg->flags & PKGCONF_PKG_PROPF_VIRTUAL)
-		return;
-
-	if (pkg->id != NULL)
-		free(pkg->id);
-
-	if (pkg->filename != NULL)
-		free(pkg->filename);
-
-	if (pkg->realname != NULL)
-		free(pkg->realname);
-
-	if (pkg->version != NULL)
-		free(pkg->version);
-
-	if (pkg->description != NULL)
-		free(pkg->description);
-
-	if (pkg->url != NULL)
-		free(pkg->url);
-
-	if (pkg->pc_filedir != NULL)
-		free(pkg->pc_filedir);
-
-	free(pkg);
-}
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_t *pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg)
- *
- *    Adds an additional reference to the package object.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object which owns the package being referenced.
- *    :param pkgconf_pkg_t* pkg: The package object being referenced.
- *    :return: The package itself with an incremented reference count.
- *    :rtype: pkgconf_pkg_t *
- */
-pkgconf_pkg_t *
-pkgconf_pkg_ref(const pkgconf_client_t *client, pkgconf_pkg_t *pkg)
-{
-	(void) client;
-
-	pkg->refcount++;
-	return pkg;
-}
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
- *
- *    Releases a reference on the package object.  If the reference count is 0, then also free the package.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object which owns the package being dereferenced.
- *    :param pkgconf_pkg_t* pkg: The package object being dereferenced.
- *    :return: nothing
- */
-void
-pkgconf_pkg_unref(pkgconf_client_t *client, pkgconf_pkg_t *pkg)
-{
-	pkg->refcount--;
-	if (pkg->refcount <= 0)
-		pkgconf_pkg_free(client, pkg);
-}
-
-static inline pkgconf_pkg_t *
-pkgconf_pkg_try_specific_path(pkgconf_client_t *client, const char *path, const char *name)
-{
-	pkgconf_pkg_t *pkg = NULL;
-	FILE *f;
-	char locbuf[PKGCONF_ITEM_SIZE];
-	char uninst_locbuf[PKGCONF_ITEM_SIZE];
-
-	PKGCONF_TRACE(client, "trying path: %s for %s", path, name);
-
-	snprintf(locbuf, sizeof locbuf, "%s/%s" PKG_CONFIG_EXT, path, name);
-	snprintf(uninst_locbuf, sizeof uninst_locbuf, "%s/%s-uninstalled" PKG_CONFIG_EXT, path, name);
-
-	if (!(client->flags & PKGCONF_PKG_PKGF_NO_UNINSTALLED) && (f = fopen(uninst_locbuf, "r")) != NULL)
-	{
-		PKGCONF_TRACE(client, "found (uninstalled): %s", uninst_locbuf);
-		pkg = pkgconf_pkg_new_from_file(client, uninst_locbuf, f);
-		pkg->flags |= PKGCONF_PKG_PROPF_UNINSTALLED;
-	}
-	else if ((f = fopen(locbuf, "r")) != NULL)
-	{
-		PKGCONF_TRACE(client, "found: %s", locbuf);
-		pkg = pkgconf_pkg_new_from_file(client, locbuf, f);
-	}
-
-	return pkg;
-}
-
-static pkgconf_pkg_t *
-pkgconf_pkg_scan_dir(pkgconf_client_t *client, const char *path, void *data, pkgconf_pkg_iteration_func_t func)
-{
-	DIR *dir;
-	struct dirent *dirent;
-	pkgconf_pkg_t *outpkg = NULL;
-
-	dir = opendir(path);
-	if (dir == NULL)
-		return NULL;
-
-	PKGCONF_TRACE(client, "scanning dir [%s]", path);
-
-	for (dirent = readdir(dir); dirent != NULL; dirent = readdir(dir))
-	{
-		char filebuf[PKGCONF_ITEM_SIZE];
-		pkgconf_pkg_t *pkg;
-		FILE *f;
-
-		pkgconf_strlcpy(filebuf, path, sizeof filebuf);
-		pkgconf_strlcat(filebuf, "/", sizeof filebuf);
-		pkgconf_strlcat(filebuf, dirent->d_name, sizeof filebuf);
-
-		if (!str_has_suffix(filebuf, PKG_CONFIG_EXT))
-			continue;
-
-		PKGCONF_TRACE(client, "trying file [%s]", filebuf);
-
-		f = fopen(filebuf, "r");
-		if (f == NULL)
-			continue;
-
-		pkg = pkgconf_pkg_new_from_file(client, filebuf, f);
-		if (pkg != NULL)
-		{
-			if (func(pkg, data))
-			{
-				outpkg = pkg;
-				goto out;
-			}
-
-			pkgconf_pkg_unref(client, pkg);
-		}
-	}
-
-out:
-	closedir(dir);
-	return outpkg;
-}
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_t *pkgconf_scan_all(pkgconf_client_t *client, void *data, pkgconf_pkg_iteration_func_t func)
- *
- *    Iterates over all packages found in the `package directory list`, running ``func`` on them.  If ``func`` returns true,
- *    then stop iteration and return the last iterated package.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param void* data: An opaque pointer to data to provide the iteration function with.
- *    :param pkgconf_pkg_iteration_func_t func: A function which is called for each package to determine if the package matches,
- *        always return ``false`` to iterate over all packages.
- *    :return: A package object reference if one is found by the scan function, else ``NULL``.
- *    :rtype: pkgconf_pkg_t *
- */
-pkgconf_pkg_t *
-pkgconf_scan_all(pkgconf_client_t *client, void *data, pkgconf_pkg_iteration_func_t func)
-{
-	pkgconf_node_t *n;
-	pkgconf_pkg_t *pkg;
-
-	PKGCONF_FOREACH_LIST_ENTRY(client->dir_list.head, n)
-	{
-		pkgconf_path_t *pnode = n->data;
-
-		PKGCONF_TRACE(client, "scanning directory: %s", pnode->path);
-
-		if ((pkg = pkgconf_pkg_scan_dir(client, pnode->path, data, func)) != NULL)
-			return pkg;
-	}
-
-	return NULL;
-}
-
-#ifdef _WIN32
-static pkgconf_pkg_t *
-pkgconf_pkg_find_in_registry_key(pkgconf_client_t *client, HKEY hkey, const char *name)
-{
-	pkgconf_pkg_t *pkg = NULL;
-
-	HKEY key;
-	int i = 0;
-
-	char buf[16384]; /* per registry limits */
-	DWORD bufsize = sizeof buf;
-	if (RegOpenKeyEx(hkey, PKG_CONFIG_REG_KEY,
-				0, KEY_READ, &key) != ERROR_SUCCESS)
-		return NULL;
-
-	while (RegEnumValue(key, i++, buf, &bufsize, NULL, NULL, NULL, NULL)
-			== ERROR_SUCCESS)
-	{
-		char pathbuf[PKGCONF_ITEM_SIZE];
-		DWORD type;
-		DWORD pathbuflen = sizeof pathbuf;
-
-		if (RegQueryValueEx(key, buf, NULL, &type, (LPBYTE) pathbuf, &pathbuflen)
-				== ERROR_SUCCESS && type == REG_SZ)
-		{
-			pkg = pkgconf_pkg_try_specific_path(client, pathbuf, name);
-			if (pkg != NULL)
-				break;
-		}
-
-		bufsize = sizeof buf;
-	}
-
-	RegCloseKey(key);
-	return pkg;
-}
-#endif
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_t *pkgconf_pkg_find(pkgconf_client_t *client, const char *name)
- *
- *    Search for a package.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param char* name: The name of the package `atom` to use for searching.
- *    :return: A package object reference if the package was found, else ``NULL``.
- *    :rtype: pkgconf_pkg_t *
- */
-pkgconf_pkg_t *
-pkgconf_pkg_find(pkgconf_client_t *client, const char *name)
-{
-	char pathbuf[PKGCONF_ITEM_SIZE];
-	pkgconf_pkg_t *pkg = NULL;
-	pkgconf_node_t *n;
-	FILE *f;
-
-	PKGCONF_TRACE(client, "looking for: %s", name);
-
-	/* name might actually be a filename. */
-	if (str_has_suffix(name, PKG_CONFIG_EXT))
-	{
-		if ((f = fopen(name, "r")) != NULL)
-		{
-			pkgconf_pkg_t *pkg;
-
-			PKGCONF_TRACE(client, "%s is a file", name);
-
-			pkg = pkgconf_pkg_new_from_file(client, name, f);
-			if (pkg != NULL)
-			{
-				pkgconf_path_add(pkg_get_parent_dir(pkg, pathbuf, sizeof pathbuf), &client->dir_list, true);
-				return pkg;
-			}
-		}
-	}
-
-	/* check builtins */
-	if ((pkg = pkgconf_builtin_pkg_get(name)) != NULL)
-	{
-		PKGCONF_TRACE(client, "%s is a builtin", name);
-		return pkg;
-	}
-
-	/* check cache */
-	if (!(client->flags & PKGCONF_PKG_PKGF_NO_CACHE))
-	{
-		if ((pkg = pkgconf_cache_lookup(client, name)) != NULL)
-		{
-			PKGCONF_TRACE(client, "%s is cached", name);
-			return pkg;
-		}
-	}
-
-	PKGCONF_FOREACH_LIST_ENTRY(client->dir_list.head, n)
-	{
-		pkgconf_path_t *pnode = n->data;
-
-		pkg = pkgconf_pkg_try_specific_path(client, pnode->path, name);
-		if (pkg != NULL)
-			goto out;
-	}
-
-#ifdef _WIN32
-	/* support getting PKG_CONFIG_PATH from registry */
-	pkg = pkgconf_pkg_find_in_registry_key(client, HKEY_CURRENT_USER, name);
-	if (!pkg)
-		pkg = pkgconf_pkg_find_in_registry_key(client, HKEY_LOCAL_MACHINE, name);
-#endif
-
-out:
-	pkgconf_cache_add(client, pkg);
-
-	return pkg;
-}
-
-/*
- * !doc
- *
- * .. c:function:: int pkgconf_compare_version(const char *a, const char *b)
- *
- *    Compare versions using RPM version comparison rules as described in the LSB.
- *
- *    :param char* a: The first version to compare in the pair.
- *    :param char* b: The second version to compare in the pair.
- *    :return: -1 if the first version is greater, 0 if both versions are equal, 1 if the second version is greater.
- *    :rtype: int
- */
-int
-pkgconf_compare_version(const char *a, const char *b)
-{
-	char oldch1, oldch2;
-	char buf1[PKGCONF_ITEM_SIZE], buf2[PKGCONF_ITEM_SIZE];
-	char *str1, *str2;
-	char *one, *two;
-	int ret;
-	bool isnum;
-
-	/* optimization: if version matches then it's the same version. */
-	if (a == NULL)
-		return 1;
-
-	if (b == NULL)
-		return -1;
-
-	if (!strcasecmp(a, b))
-		return 0;
-
-	pkgconf_strlcpy(buf1, a, sizeof buf1);
-	pkgconf_strlcpy(buf2, b, sizeof buf2);
-
-	one = str1 = buf1;
-	two = str2 = buf2;
-
-	while (*one || *two)
-	{
-		while (*one && !isalnum((unsigned int)*one) && *one != '~')
-			one++;
-		while (*two && !isalnum((unsigned int)*two) && *two != '~')
-			two++;
-
-		if (*one == '~' || *two == '~')
-		{
-			if (*one != '~')
-				return -1;
-			if (*two != '~')
-				return 1;
-
-			one++;
-			two++;
-			continue;
-		}
-
-		if (!(*one && *two))
-			break;
-
-		str1 = one;
-		str2 = two;
-
-		if (isdigit((unsigned int)*str1))
-		{
-			while (*str1 && isdigit((unsigned int)*str1))
-				str1++;
-
-			while (*str2 && isdigit((unsigned int)*str2))
-				str2++;
-
-			isnum = true;
-		}
-		else
-		{
-			while (*str1 && isalpha((unsigned int)*str1))
-				str1++;
-
-			while (*str2 && isalpha((unsigned int)*str2))
-				str2++;
-
-			isnum = false;
-		}
-
-		oldch1 = *str1;
-		oldch2 = *str2;
-
-		*str1 = '\0';
-		*str2 = '\0';
-
-		if (one == str1)
-			return -1;
-
-		if (two == str2)
-			return (isnum ? 1 : -1);
-
-		if (isnum)
-		{
-			int onelen, twolen;
-
-			while (*one == '0')
-				one++;
-
-			while (*two == '0')
-				two++;
-
-			onelen = strlen(one);
-			twolen = strlen(two);
-
-			if (onelen > twolen)
-				return 1;
-			else if (twolen > onelen)
-				return -1;
-		}
-
-		ret = strcmp(one, two);
-		if (ret)
-			return ret;
-
-		*str1 = oldch1;
-		*str2 = oldch2;
-
-		one = str1;
-		two = str2;
-	}
-
-	if ((!*one) && (!*two))
-		return 0;
-
-	if (!*one)
-		return -1;
-
-	return 1;
-}
-
-static pkgconf_pkg_t pkg_config_virtual = {
-	.id = "pkg-config",
-	.realname = "pkg-config",
-	.description = "virtual package defining pkg-config API version supported",
-	.url = PACKAGE_BUGREPORT,
-	.version = PACKAGE_VERSION,
-	.flags = PKGCONF_PKG_PROPF_STATIC,
-	.vars = {
-		.head = &(pkgconf_node_t){
-			.prev = NULL,
-			.next = NULL,
-			.data = &(pkgconf_tuple_t){
-				.key = "pc_path",
-				.value = PKG_DEFAULT_PATH,
-			},
-		},
-		.tail = NULL,
-	},
-};
-
-static pkgconf_pkg_t pkgconf_virtual = {
-	.id = "pkgconf",
-	.realname = "pkgconf",
-	.description = "virtual package defining pkgconf API version supported",
-	.url = PACKAGE_BUGREPORT,
-	.version = PACKAGE_VERSION,
-	.flags = PKGCONF_PKG_PROPF_STATIC,
-	.vars = {
-		.head = &(pkgconf_node_t){
-			.prev = NULL,
-			.next = NULL,
-			.data = &(pkgconf_tuple_t){
-				.key = "pc_path",
-				.value = PKG_DEFAULT_PATH,
-			},
-		},
-		.tail = NULL,
-	},
-};
-
-typedef struct {
-	const char *name;
-	pkgconf_pkg_t *pkg;
-} pkgconf_builtin_pkg_pair_t;
-
-/* keep these in alphabetical order */
-static const pkgconf_builtin_pkg_pair_t pkgconf_builtin_pkg_pair_set[] = {
-	{"pkg-config", &pkg_config_virtual},
-	{"pkgconf", &pkgconf_virtual},
-};
-
-static int pkgconf_builtin_pkg_pair_cmp(const void *key, const void *ptr)
-{
-	const pkgconf_builtin_pkg_pair_t *pair = ptr;
-	return strcasecmp(key, pair->name);
-}
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_t *pkgconf_builtin_pkg_get(const char *name)
- *
- *    Looks up a built-in package.  The package should not be freed or dereferenced.
- *
- *    :param char* name: An atom corresponding to a built-in package to search for.
- *    :return: the built-in package if present, else ``NULL``.
- *    :rtype: pkgconf_pkg_t *
- */
-pkgconf_pkg_t *
-pkgconf_builtin_pkg_get(const char *name)
-{
-	const pkgconf_builtin_pkg_pair_t *pair = bsearch(name, pkgconf_builtin_pkg_pair_set,
-		PKGCONF_ARRAY_SIZE(pkgconf_builtin_pkg_pair_set), sizeof(pkgconf_builtin_pkg_pair_t),
-		pkgconf_builtin_pkg_pair_cmp);
-
-	return (pair != NULL) ? pair->pkg : NULL;
-}
-
-typedef bool (*pkgconf_vercmp_res_func_t)(const char *a, const char *b);
-
-typedef struct {
-	const char *name;
-	pkgconf_pkg_comparator_t compare;
-} pkgconf_pkg_comparator_pair_t;
-
-static const pkgconf_pkg_comparator_pair_t pkgconf_pkg_comparator_names[] = {
-	{"!=",		PKGCONF_CMP_NOT_EQUAL},
-	{"(any)",	PKGCONF_CMP_ANY},
-	{"<",		PKGCONF_CMP_LESS_THAN},
-	{"<=",		PKGCONF_CMP_LESS_THAN_EQUAL},
-	{"=",		PKGCONF_CMP_EQUAL},
-	{">",		PKGCONF_CMP_GREATER_THAN},
-	{">=",		PKGCONF_CMP_GREATER_THAN_EQUAL},
-};
-
-static int pkgconf_pkg_comparator_pair_namecmp(const void *key, const void *ptr)
-{
-	const pkgconf_pkg_comparator_pair_t *pair = ptr;
-	return strcmp(key, pair->name);
-}
-
-static bool pkgconf_pkg_comparator_lt(const char *a, const char *b)
-{
-	return (pkgconf_compare_version(a, b) < 0);
-}
-
-static bool pkgconf_pkg_comparator_gt(const char *a, const char *b)
-{
-	return (pkgconf_compare_version(a, b) > 0);
-}
-
-static bool pkgconf_pkg_comparator_lte(const char *a, const char *b)
-{
-	return (pkgconf_compare_version(a, b) <= 0);
-}
-
-static bool pkgconf_pkg_comparator_gte(const char *a, const char *b)
-{
-	return (pkgconf_compare_version(a, b) >= 0);
-}
-
-static bool pkgconf_pkg_comparator_eq(const char *a, const char *b)
-{
-	return (pkgconf_compare_version(a, b) == 0);
-}
-
-static bool pkgconf_pkg_comparator_ne(const char *a, const char *b)
-{
-	return (pkgconf_compare_version(a, b) != 0);
-}
-
-static bool pkgconf_pkg_comparator_any(const char *a, const char *b)
-{
-	(void) a;
-	(void) b;
-
-	return true;
-}
-
-static bool pkgconf_pkg_comparator_none(const char *a, const char *b)
-{
-	(void) a;
-	(void) b;
-
-	return false;
-}
-
-static const pkgconf_vercmp_res_func_t pkgconf_pkg_comparator_impls[] = {
-	[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_any,
-	[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
-	[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
-	[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
-	[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
-	[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_eq,
-	[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_ne,
-};
-
-/*
- * !doc
- *
- * .. c:function:: const char *pkgconf_pkg_get_comparator(const pkgconf_dependency_t *pkgdep)
- *
- *    Returns the comparator used in a depgraph dependency node as a string.
- *
- *    :param pkgconf_dependency_t* pkgdep: The depgraph dependency node to return the comparator for.
- *    :return: A string matching the comparator or ``"???"``.
- *    :rtype: char *
- */
-const char *
-pkgconf_pkg_get_comparator(const pkgconf_dependency_t *pkgdep)
-{
-	if (pkgdep->compare >= PKGCONF_ARRAY_SIZE(pkgconf_pkg_comparator_names))
-		return "???";
-
-	return pkgconf_pkg_comparator_names[pkgdep->compare].name;
-}
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_comparator_t pkgconf_pkg_comparator_lookup_by_name(const char *name)
- *
- *    Look up the appropriate comparator bytecode in the comparator set (defined
- *    in ``pkg.c``, see ``pkgconf_pkg_comparator_names`` and ``pkgconf_pkg_comparator_impls``).
- *
- *    :param char* name: The comparator to look up by `name`.
- *    :return: The comparator bytecode if found, else ``PKGCONF_CMP_ANY``.
- *    :rtype: pkgconf_pkg_comparator_t
- */
-pkgconf_pkg_comparator_t
-pkgconf_pkg_comparator_lookup_by_name(const char *name)
-{
-	const pkgconf_pkg_comparator_pair_t *p = bsearch(name, pkgconf_pkg_comparator_names,
-		PKGCONF_ARRAY_SIZE(pkgconf_pkg_comparator_names), sizeof(pkgconf_pkg_comparator_pair_t),
-		pkgconf_pkg_comparator_pair_namecmp);
-
-	return (p != NULL) ? p->compare : PKGCONF_CMP_ANY;
-}
-
-typedef struct {
-	pkgconf_dependency_t *pkgdep;
-} pkgconf_pkg_scan_providers_ctx_t;
-
-typedef struct {
-	const pkgconf_vercmp_res_func_t rulecmp[PKGCONF_CMP_COUNT];
-	const pkgconf_vercmp_res_func_t depcmp[PKGCONF_CMP_COUNT];
-} pkgconf_pkg_provides_vermatch_rule_t;
-
-static const pkgconf_pkg_provides_vermatch_rule_t pkgconf_pkg_provides_vermatch_rules[] = {
-	[PKGCONF_CMP_ANY] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-                },
-		.depcmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-                },
-	},
-	[PKGCONF_CMP_LESS_THAN] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
-		},
-		.depcmp = {
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_gte,
-		},
-	},
-	[PKGCONF_CMP_GREATER_THAN] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
-		},
-		.depcmp = {
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_lte,
-		},
-	},
-	[PKGCONF_CMP_LESS_THAN_EQUAL] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
-		},
-		.depcmp = {
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_gt,
-		},
-	},
-	[PKGCONF_CMP_GREATER_THAN_EQUAL] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
-		},
-		.depcmp = {
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_gte,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_gte,
-			[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_gte,
-			[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_lt,
-		},
-	},
-	[PKGCONF_CMP_EQUAL] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
-			[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_eq,
-			[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_ne
-		},
-		.depcmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-                },
-	},
-	[PKGCONF_CMP_NOT_EQUAL] = {
-		.rulecmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-			[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_gte,
-			[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_lte,
-			[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_gt,
-			[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_lt,
-			[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_ne,
-			[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_eq
-		},
-		.depcmp = {
-			[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_none,
-                },
-	},
-};
-
-/*
- * pkgconf_pkg_scan_provides_vercmp(pkgdep, provider)
- *
- * compare a provides node against the requested dependency node.
- *
- * XXX: maybe handle PKGCONF_CMP_ANY in a versioned comparison
- */
-static bool
-pkgconf_pkg_scan_provides_vercmp(const pkgconf_dependency_t *pkgdep, const pkgconf_dependency_t *provider)
-{
-	const pkgconf_pkg_provides_vermatch_rule_t *rule = &pkgconf_pkg_provides_vermatch_rules[pkgdep->compare];
-
-	if (rule->depcmp[provider->compare] != NULL &&
-	    !rule->depcmp[provider->compare](provider->version, pkgdep->version))
-		return false;
-
-	if (rule->rulecmp[provider->compare] != NULL &&
-	    !rule->rulecmp[provider->compare](pkgdep->version, provider->version))
-		return false;
-
-	return true;
-}
-
-/*
- * pkgconf_pkg_scan_provides_entry(pkg, ctx)
- *
- * attempt to match a single package's Provides rules against the requested dependency node.
- */
-static bool
-pkgconf_pkg_scan_provides_entry(const pkgconf_pkg_t *pkg, const pkgconf_pkg_scan_providers_ctx_t *ctx)
-{
-	const pkgconf_dependency_t *pkgdep = ctx->pkgdep;
-	pkgconf_node_t *node;
-
-	PKGCONF_FOREACH_LIST_ENTRY(pkg->provides.head, node)
-	{
-		const pkgconf_dependency_t *provider = node->data;
-		if (!strcmp(provider->package, pkgdep->package))
-			return pkgconf_pkg_scan_provides_vercmp(pkgdep, provider);
-	}
-
-	return false;
-}
-
-/*
- * pkgconf_pkg_scan_providers(client, pkgdep, eflags)
- *
- * scan all available packages to see if a Provides rule matches the pkgdep.
- */
-static pkgconf_pkg_t *
-pkgconf_pkg_scan_providers(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int *eflags)
-{
-	pkgconf_pkg_t *pkg;
-	pkgconf_pkg_scan_providers_ctx_t ctx = {
-		.pkgdep = pkgdep,
-	};
-
-	pkg = pkgconf_scan_all(client, &ctx, (pkgconf_pkg_iteration_func_t) pkgconf_pkg_scan_provides_entry);
-	if (pkg != NULL)
-		return pkg;
-
-	if (eflags != NULL)
-		*eflags |= PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND;
-
-	return NULL;
-}
-
-/*
- * !doc
- *
- * .. c:function:: pkgconf_pkg_t *pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int *eflags)
- *
- *    Verify a pkgconf_dependency_t node in the depgraph.  If the dependency is solvable,
- *    return the appropriate ``pkgconf_pkg_t`` object, else ``NULL``.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_dependency_t* pkgdep: The dependency graph node to solve.
- *    :param uint* eflags: An optional pointer that, if set, will be populated with an error code from the resolver.
- *    :return: On success, the appropriate ``pkgconf_pkg_t`` object to solve the dependency, else ``NULL``.
- *    :rtype: pkgconf_pkg_t *
- */
-pkgconf_pkg_t *
-pkgconf_pkg_verify_dependency(pkgconf_client_t *client, pkgconf_dependency_t *pkgdep, unsigned int *eflags)
-{
-	pkgconf_pkg_t *pkg = NULL;
-
-	if (eflags != NULL)
-		*eflags = PKGCONF_PKG_ERRF_OK;
-
-	PKGCONF_TRACE(client, "trying to verify dependency: %s", pkgdep->package);
-
-	pkg = pkgconf_pkg_find(client, pkgdep->package);
-	if (pkg == NULL)
-	{
-		if (client->flags & PKGCONF_PKG_PKGF_SKIP_PROVIDES)
-		{
-			if (eflags != NULL)
-				*eflags |= PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND;
-
-			return NULL;
-		}
-
-		return pkgconf_pkg_scan_providers(client, pkgdep, eflags);
-	}
-
-	if (pkg->id == NULL)
-		pkg->id = strdup(pkgdep->package);
-
-	if (pkgconf_pkg_comparator_impls[pkgdep->compare](pkg->version, pkgdep->version) == true)
-		return pkg;
-
-	if (eflags != NULL)
-		*eflags |= PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH;
-
-	return pkg;
-}
-
-/*
- * !doc
- *
- * .. c:function:: unsigned int pkgconf_pkg_verify_graph(pkgconf_client_t *client, pkgconf_pkg_t *root, int depth)
- *
- *    Verify the graph dependency nodes are satisfiable by walking the tree using
- *    ``pkgconf_pkg_traverse()``.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_pkg_t* root: The root entry in the package dependency graph which should contain the top-level dependencies to resolve.
- *    :param int depth: The maximum allowed depth for dependency resolution.
- *    :return: On success, ``PKGCONF_PKG_ERRF_OK`` (0), else an error code.
- *    :rtype: unsigned int
- */
-unsigned int
-pkgconf_pkg_verify_graph(pkgconf_client_t *client, pkgconf_pkg_t *root, int depth)
-{
-	return pkgconf_pkg_traverse(client, root, NULL, NULL, depth);
-}
-
-static unsigned int
-pkgconf_pkg_report_graph_error(pkgconf_client_t *client, pkgconf_pkg_t *parent, pkgconf_pkg_t *pkg, pkgconf_dependency_t *node, unsigned int eflags)
-{
-	if (eflags & PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND)
-	{
-		if (!(client->flags & PKGCONF_PKG_PKGF_SIMPLIFY_ERRORS) & !client->already_sent_notice)
-		{
-			pkgconf_error(client, "Package %s was not found in the pkg-config search path.\n", node->package);
-			pkgconf_error(client, "Perhaps you should add the directory containing `%s.pc'\n", node->package);
-			pkgconf_error(client, "to the PKG_CONFIG_PATH environment variable\n");
-			client->already_sent_notice = true;
-		}
-
-		pkgconf_error(client, "Package '%s', required by '%s', not found\n", node->package, parent->id);
-		pkgconf_audit_log(client, "%s NOT-FOUND\n", node->package);
-	}
-	else if (eflags & PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH)
-	{
-		pkgconf_error(client, "Package dependency requirement '%s %s %s' could not be satisfied.\n",
-			node->package, pkgconf_pkg_get_comparator(node), node->version);
-
-		if (pkg != NULL)
-			pkgconf_error(client, "Package '%s' has version '%s', required version is '%s %s'\n",
-				node->package, pkg->version, pkgconf_pkg_get_comparator(node), node->version);
-	}
-
-	if (pkg != NULL)
-		pkgconf_pkg_unref(client, pkg);
-
-	return eflags;
-}
-
-static inline unsigned int
-pkgconf_pkg_walk_list(pkgconf_client_t *client,
-	pkgconf_pkg_t *parent,
-	pkgconf_list_t *deplist,
-	pkgconf_pkg_traverse_func_t func,
-	void *data,
-	int depth)
-{
-	unsigned int eflags = PKGCONF_PKG_ERRF_OK;
-	pkgconf_node_t *node;
-
-	PKGCONF_FOREACH_LIST_ENTRY(deplist->head, node)
-	{
-		unsigned int eflags_local = PKGCONF_PKG_ERRF_OK;
-		pkgconf_dependency_t *depnode = node->data;
-		pkgconf_pkg_t *pkgdep;
-
-		if (*depnode->package == '\0')
-			continue;
-
-		pkgdep = pkgconf_pkg_verify_dependency(client, depnode, &eflags_local);
-
-		eflags |= eflags_local;
-		if (eflags_local != PKGCONF_PKG_ERRF_OK && !(client->flags & PKGCONF_PKG_PKGF_SKIP_ERRORS))
-		{
-			pkgconf_pkg_report_graph_error(client, parent, pkgdep, depnode, eflags_local);
-			continue;
-		}
-		if (pkgdep == NULL)
-			continue;
-
-		if (pkgdep->flags & PKGCONF_PKG_PROPF_SEEN)
-		{
-			pkgconf_pkg_unref(client, pkgdep);
-			continue;
-		}
-
-		pkgconf_audit_log_dependency(client, pkgdep, depnode);
-
-		pkgdep->flags |= PKGCONF_PKG_PROPF_SEEN;
-		eflags |= pkgconf_pkg_traverse(client, pkgdep, func, data, depth - 1);
-		pkgdep->flags &= ~PKGCONF_PKG_PROPF_SEEN;
-		pkgconf_pkg_unref(client, pkgdep);
-	}
-
-	return eflags;
-}
-
-static inline unsigned int
-pkgconf_pkg_walk_conflicts_list(pkgconf_client_t *client,
-	pkgconf_pkg_t *root, pkgconf_list_t *deplist)
-{
-	unsigned int eflags;
-	pkgconf_node_t *node, *childnode;
-
-	PKGCONF_FOREACH_LIST_ENTRY(deplist->head, node)
-	{
-		pkgconf_dependency_t *parentnode = node->data;
-
-		if (*parentnode->package == '\0')
-			continue;
-
-		PKGCONF_FOREACH_LIST_ENTRY(root->requires.head, childnode)
-		{
-			pkgconf_pkg_t *pkgdep;
-			pkgconf_dependency_t *depnode = childnode->data;
-
-			if (*depnode->package == '\0' || strcmp(depnode->package, parentnode->package))
-				continue;
-
-			pkgdep = pkgconf_pkg_verify_dependency(client, parentnode, &eflags);
-			if (eflags == PKGCONF_PKG_ERRF_OK)
-			{
-				pkgconf_error(client, "Version '%s' of '%s' conflicts with '%s' due to satisfying conflict rule '%s %s%s%s'.\n",
-					pkgdep->version, pkgdep->realname, root->realname, parentnode->package, pkgconf_pkg_get_comparator(parentnode),
-					parentnode->version != NULL ? " " : "", parentnode->version != NULL ? parentnode->version : "");
-				pkgconf_error(client, "It may be possible to ignore this conflict and continue, try the\n");
-				pkgconf_error(client, "PKG_CONFIG_IGNORE_CONFLICTS environment variable.\n");
-
-				pkgconf_pkg_unref(client, pkgdep);
-
-				return PKGCONF_PKG_ERRF_PACKAGE_CONFLICT;
-			}
-
-			pkgconf_pkg_unref(client, pkgdep);
-		}
-	}
-
-	return PKGCONF_PKG_ERRF_OK;
-}
-
-/*
- * !doc
- *
- * .. c:function:: unsigned int pkgconf_pkg_traverse(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_pkg_traverse_func_t func, void *data, int maxdepth)
- *
- *    Walk and resolve the dependency graph up to `maxdepth` levels.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_pkg_t* root: The root of the dependency graph.
- *    :param pkgconf_pkg_traverse_func_t func: A traversal function to call for each resolved node in the dependency graph.
- *    :param void* data: An opaque pointer to data to be passed to the traversal function.
- *    :param int maxdepth: The maximum depth to walk the dependency graph for.  -1 means infinite recursion.
- *    :return: ``PKGCONF_PKG_ERRF_OK`` on success, else an error code.
- *    :rtype: unsigned int
- */
-unsigned int
-pkgconf_pkg_traverse(pkgconf_client_t *client,
-	pkgconf_pkg_t *root,
-	pkgconf_pkg_traverse_func_t func,
-	void *data,
-	int maxdepth)
-{
-	unsigned int eflags = PKGCONF_PKG_ERRF_OK;
-
-	if (maxdepth == 0)
-		return eflags;
-
-	PKGCONF_TRACE(client, "%s: level %d", root->id, maxdepth);
-
-	if ((root->flags & PKGCONF_PKG_PROPF_VIRTUAL) != PKGCONF_PKG_PROPF_VIRTUAL || (client->flags & PKGCONF_PKG_PKGF_SKIP_ROOT_VIRTUAL) != PKGCONF_PKG_PKGF_SKIP_ROOT_VIRTUAL)
-	{
-		if (func != NULL)
-			func(client, root, data);
-	}
-
-	if (!(client->flags & PKGCONF_PKG_PKGF_SKIP_CONFLICTS))
-	{
-		eflags = pkgconf_pkg_walk_conflicts_list(client, root, &root->conflicts);
-		if (eflags != PKGCONF_PKG_ERRF_OK)
-			return eflags;
-	}
-
-	PKGCONF_TRACE(client, "%s: walking requires list", root->id);
-	eflags = pkgconf_pkg_walk_list(client, root, &root->requires, func, data, maxdepth);
-	if (eflags != PKGCONF_PKG_ERRF_OK)
-		return eflags;
-
-	if (client->flags & PKGCONF_PKG_PKGF_SEARCH_PRIVATE)
-	{
-		PKGCONF_TRACE(client, "%s: walking requires.private list", root->id);
-
-		/* XXX: ugly */
-		client->flags |= PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE;
-		eflags = pkgconf_pkg_walk_list(client, root, &root->requires_private, func, data, maxdepth);
-		client->flags &= ~PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE;
-
-		if (eflags != PKGCONF_PKG_ERRF_OK)
-			return eflags;
-	}
-
-	return eflags;
-}
-
-static void
-pkgconf_pkg_cflags_collect(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data)
-{
-	pkgconf_list_t *list = data;
-	pkgconf_node_t *node;
-
-	PKGCONF_FOREACH_LIST_ENTRY(pkg->cflags.head, node)
-	{
-		pkgconf_fragment_t *frag = node->data;
-		pkgconf_fragment_copy(client, list, frag, false);
-	}
-}
-
-static void
-pkgconf_pkg_cflags_private_collect(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data)
-{
-	pkgconf_list_t *list = data;
-	pkgconf_node_t *node;
-
-	PKGCONF_FOREACH_LIST_ENTRY(pkg->cflags_private.head, node)
-	{
-		pkgconf_fragment_t *frag = node->data;
-		pkgconf_fragment_copy(client, list, frag, true);
-	}
-}
-
-/*
- * !doc
- *
- * .. c:function:: int pkgconf_pkg_cflags(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth)
- *
- *    Walks a dependency graph and extracts relevant ``CFLAGS`` fragments.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_pkg_t* root: The root of the dependency graph.
- *    :param pkgconf_list_t* list: The fragment list to add the extracted ``CFLAGS`` fragments to.
- *    :param int maxdepth: The maximum allowed depth for dependency resolution.  -1 means infinite recursion.
- *    :return: ``PKGCONF_PKG_ERRF_OK`` if successful, otherwise an error code.
- *    :rtype: unsigned int
- */
-unsigned int
-pkgconf_pkg_cflags(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth)
-{
-	unsigned int eflag;
-
-	eflag = pkgconf_pkg_traverse(client, root, pkgconf_pkg_cflags_collect, list, maxdepth);
-	if (eflag != PKGCONF_PKG_ERRF_OK)
-		pkgconf_fragment_free(list);
-
-	if (client->flags & PKGCONF_PKG_PKGF_MERGE_PRIVATE_FRAGMENTS)
-	{
-		eflag = pkgconf_pkg_traverse(client, root, pkgconf_pkg_cflags_private_collect, list, maxdepth);
-		if (eflag != PKGCONF_PKG_ERRF_OK)
-			pkgconf_fragment_free(list);
-	}
-
-	return eflag;
-}
-
-static void
-pkgconf_pkg_libs_collect(pkgconf_client_t *client, pkgconf_pkg_t *pkg, void *data)
-{
-	pkgconf_list_t *list = data;
-	pkgconf_node_t *node;
-
-	PKGCONF_FOREACH_LIST_ENTRY(pkg->libs.head, node)
-	{
-		pkgconf_fragment_t *frag = node->data;
-		pkgconf_fragment_copy(client, list, frag, (client->flags & PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE) != 0);
-	}
-
-	if (client->flags & PKGCONF_PKG_PKGF_MERGE_PRIVATE_FRAGMENTS)
-	{
-		PKGCONF_FOREACH_LIST_ENTRY(pkg->libs_private.head, node)
-		{
-			pkgconf_fragment_t *frag = node->data;
-			pkgconf_fragment_copy(client, list, frag, true);
-		}
-	}
-}
-
-/*
- * !doc
- *
- * .. c:function:: int pkgconf_pkg_libs(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth)
- *
- *    Walks a dependency graph and extracts relevant ``LIBS`` fragments.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_pkg_t* root: The root of the dependency graph.
- *    :param pkgconf_list_t* list: The fragment list to add the extracted ``LIBS`` fragments to.
- *    :param int maxdepth: The maximum allowed depth for dependency resolution.  -1 means infinite recursion.
- *    :return: ``PKGCONF_PKG_ERRF_OK`` if successful, otherwise an error code.
- *    :rtype: unsigned int
- */
-unsigned int
-pkgconf_pkg_libs(pkgconf_client_t *client, pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth)
-{
-	unsigned int eflag;
-
-	eflag = pkgconf_pkg_traverse(client, root, pkgconf_pkg_libs_collect, list, maxdepth);
-
-	if (eflag != PKGCONF_PKG_ERRF_OK)
-	{
-		pkgconf_fragment_free(list);
-		return eflag;
-	}
-
-	return eflag;
-}
diff --git a/libpkgconf/queue.c b/libpkgconf/queue.c
index fb6eefd..1bfcb30 100644
--- a/libpkgconf/queue.c
+++ b/libpkgconf/queue.c
@@ -77,10 +77,10 @@ pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_li
 		pkgconf_queue_t *pkgq;
 
 		pkgq = iter->data;
-		pkgconf_dependency_parse(client, world, &world->requires_, pkgq->package);
+		pkgconf_dependency_parse(client, world, &world->required, pkgq->package);
 	}
 
-	return (world->requires_.head != NULL);
+	return (world->required.head != NULL);
 }
 
 /*
diff --git a/libpkgconf/queue.c.orig b/libpkgconf/queue.c.orig
deleted file mode 100644
index 73507fa..0000000
--- a/libpkgconf/queue.c.orig
+++ /dev/null
@@ -1,195 +0,0 @@
-/*
- * queue.c
- * compilation of a list of packages into a world dependency set
- *
- * Copyright (c) 2012 pkgconf authors (see AUTHORS).
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * This software is provided 'as is' and without any warranty, express or
- * implied.  In no event shall the authors be liable for any damages arising
- * from the use of this software.
- */
-
-#include <libpkgconf/stdinc.h>
-#include <libpkgconf/libpkgconf.h>
-
-/*
- * !doc
- *
- * libpkgconf `queue` module
- * =========================
- *
- * The `queue` module provides an interface that allows easily building a dependency graph from an
- * arbitrary set of dependencies.  It also provides support for doing "preflight" checks on the entire
- * dependency graph prior to working with it.
- *
- * Using the `queue` module functions is the recommended way of working with dependency graphs.
- */
-
-typedef struct {
-	pkgconf_node_t iter;
-	char *package;
-} pkgconf_queue_t;
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_queue_push(pkgconf_list_t *list, const char *package)
- *
- *    Pushes a requested dependency onto the dependency resolver's queue.
- *
- *    :param pkgconf_list_t* list: the dependency resolution queue to add the package request to.
- *    :param char* package: the dependency atom requested
- *    :return: nothing
- */
-void
-pkgconf_queue_push(pkgconf_list_t *list, const char *package)
-{
-	pkgconf_queue_t *pkgq = calloc(sizeof(pkgconf_queue_t), 1);
-
-	pkgq->package = strdup(package);
-	pkgconf_node_insert_tail(&pkgq->iter, pkgq, list);
-}
-
-/*
- * !doc
- *
- * .. c:function:: bool pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list)
- *
- *    Compile a dependency resolution queue into a dependency resolution problem if possible, otherwise report an error.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_pkg_t* world: The designated root of the dependency graph.
- *    :param pkgconf_list_t* list: The list of dependency requests to consider.
- *    :return: true if the built dependency resolution problem is consistent, else false
- *    :rtype: bool
- */
-bool
-pkgconf_queue_compile(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list)
-{
-	pkgconf_node_t *iter;
-
-	PKGCONF_FOREACH_LIST_ENTRY(list->head, iter)
-	{
-		pkgconf_queue_t *pkgq;
-
-		pkgq = iter->data;
-		pkgconf_dependency_parse(client, world, &world->requires, pkgq->package);
-	}
-
-	return (world->requires.head != NULL);
-}
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_queue_free(pkgconf_list_t *list)
- *
- *    Release any memory related to a dependency resolution queue.
- *
- *    :param pkgconf_list_t* list: The dependency resolution queue to release.
- *    :return: nothing
- */
-void
-pkgconf_queue_free(pkgconf_list_t *list)
-{
-	pkgconf_node_t *node, *tnode;
-
-	PKGCONF_FOREACH_LIST_ENTRY_SAFE(list->head, tnode, node)
-	{
-		pkgconf_queue_t *pkgq = node->data;
-
-		free(pkgq->package);
-		free(pkgq);
-	}
-}
-
-static inline unsigned int
-pkgconf_queue_verify(pkgconf_client_t *client, pkgconf_pkg_t *world, pkgconf_list_t *list, int maxdepth)
-{
-	if (!pkgconf_queue_compile(client, world, list))
-		return PKGCONF_PKG_ERRF_DEPGRAPH_BREAK;
-
-	return pkgconf_pkg_verify_graph(client, world, maxdepth);
-}
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data)
- *
- *    Attempt to compile a dependency resolution queue into a dependency resolution problem, then attempt to solve the problem and
- *    feed the solution to a callback function if a complete dependency graph is found.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_list_t* list: The list of dependency requests to consider.
- *    :param pkgconf_queue_apply_func_t func: The callback function to call if a solution is found by the dependency resolver.
- *    :param int maxdepth: The maximum allowed depth for the dependency resolver.  A depth of -1 means unlimited.
- *    :param void* data: An opaque pointer which is passed to the callback function.
- *    :returns: true if the dependency resolver found a solution, otherwise false.
- *    :rtype: bool
- */
-bool
-pkgconf_queue_apply(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data)
-{
-	pkgconf_pkg_t world = {
-		.id = "virtual:world",
-		.realname = "virtual world package",
-		.flags = PKGCONF_PKG_PROPF_STATIC | PKGCONF_PKG_PROPF_VIRTUAL,
-	};
-
-	/* if maxdepth is one, then we will not traverse deeper than our virtual package. */
-	if (!maxdepth)
-		maxdepth = -1;
-
-	if (pkgconf_queue_verify(client, &world, list, maxdepth) != PKGCONF_PKG_ERRF_OK)
-		return false;
-
-	if (!func(client, &world, data, maxdepth))
-	{
-		pkgconf_pkg_free(client, &world);
-		return false;
-	}
-
-	pkgconf_pkg_free(client, &world);
-
-	return true;
-}
-
-/*
- * !doc
- *
- * .. c:function:: void pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, pkgconf_queue_apply_func_t func, int maxdepth, void *data)
- *
- *    Attempt to compile a dependency resolution queue into a dependency resolution problem, then attempt to solve the problem.
- *
- *    :param pkgconf_client_t* client: The pkgconf client object to use for dependency resolution.
- *    :param pkgconf_list_t* list: The list of dependency requests to consider.
- *    :param int maxdepth: The maximum allowed depth for the dependency resolver.  A depth of -1 means unlimited.
- *    :returns: true if the dependency resolver found a solution, otherwise false.
- *    :rtype: bool
- */
-bool
-pkgconf_queue_validate(pkgconf_client_t *client, pkgconf_list_t *list, int maxdepth)
-{
-	bool retval = true;
-	pkgconf_pkg_t world = {
-		.id = "virtual:world",
-		.realname = "virtual world package",
-		.flags = PKGCONF_PKG_PROPF_STATIC | PKGCONF_PKG_PROPF_VIRTUAL,
-	};
-
-	/* if maxdepth is one, then we will not traverse deeper than our virtual package. */
-	if (!maxdepth)
-		maxdepth = -1;
-
-	if (pkgconf_queue_verify(client, &world, list, maxdepth) != PKGCONF_PKG_ERRF_OK)
-		retval = false;
-
-	pkgconf_pkg_free(client, &world);
-
-	return retval;
-}
diff --git a/libpkgconf/tuple.c b/libpkgconf/tuple.c
index 7fbc71b..a4b4250 100644
--- a/libpkgconf/tuple.c
+++ b/libpkgconf/tuple.c
@@ -158,6 +158,8 @@ pkgconf_tuple_add(const pkgconf_client_t *client, pkgconf_list_t *list, const ch
 
 	pkgconf_tuple_find_delete(list, key);
 
+	PKGCONF_TRACE(client, "adding tuple to @%p: %s => %s (parsed? %d)", list, key, value, parse);
+
 	tuple->key = strdup(key);
 	if (parse)
 		tuple->value = pkgconf_tuple_parse(client, list, value);
diff --git a/tests/basic/driver.c b/tests/basic/driver.c
index 1f861de..c9810ce 100644
--- a/tests/basic/driver.c
+++ b/tests/basic/driver.c
@@ -37,7 +37,9 @@ error_handler (const char* msg, const pkgconf_client_t* c, const void* d)
 static void
 print_and_free (pkgconf_list_t* list)
 {
-  char* buf = pkgconf_fragment_render (list, /* escape */ true);
+  char* buf = pkgconf_fragment_render (list,
+                                       true /* escape */,
+                                       NULL /* options */);
   printf("%s", buf);
   free (buf);
 
@@ -65,7 +67,7 @@ int
 main (int argc, const char* argv[])
 {
   pkgconf_client_t* c =
-    pkgconf_client_new (error_handler, /* error_handler_data */ NULL);
+    pkgconf_client_new (error_handler, NULL /* error_handler_data */);
 
   assert (c != NULL);