Fix mkanylink() to complete relative target against link directory when create hardlink or copy

5 files changed, 23 insertions, 9 deletions

diff --git a/libbutl/builtin.cxx b/libbutl/builtin.cxx
index f1b6b63..9efa697 100644
--- a/libbutl/builtin.cxx
+++ b/libbutl/builtin.cxx
@@ -277,7 +277,7 @@ namespace butl
   }
 
   // Return the current working directory if wd is empty and wd otherwise,
-  // completed against the current directory if it is relative. Fail if
+  // completed using the current directory if it is relative. Fail if
   // std::system_error is thrown by the underlying function call.
   //
   dir_path
@@ -779,7 +779,7 @@ namespace butl
     assert (link.absolute () && link.normalized ());
 
     // Determine the target type, fail if the target doesn't exist. Note that
-    // to do that we need to complete a relative target path against the link
+    // to do that we need to complete a relative target path using the link
     // directory making the target path absolute.
     //
     const path& atp (target.relative ()
diff --git a/libbutl/command.cxx b/libbutl/command.cxx
index 8dcfd05..bb5287c 100644
--- a/libbutl/command.cxx
+++ b/libbutl/command.cxx
@@ -137,7 +137,7 @@ namespace butl
 
     // Sort the remaining command line elements into the arguments and
     // redirects, performing the substitutions. Complete relative redirects
-    // against CWD and use the rightmost redirect.
+    // using CWD and use the rightmost redirect.
     //
     vector<string> args;
 
diff --git a/libbutl/command.mxx b/libbutl/command.mxx
index b215817..02c8eb8 100644
--- a/libbutl/command.mxx
+++ b/libbutl/command.mxx
@@ -55,7 +55,7 @@ LIBBUTL_MODEXPORT namespace butl
   // possible substitutions (so the redirect character cannot be the result of
   // a substitution; see below).
   //
-  // The relative redirect file paths are completed against the command
+  // The relative redirect file paths are completed using the command
   // current working directory. Note that if it is altered via the process
   // environment, then the new value is used.
   //
diff --git a/libbutl/filesystem.cxx b/libbutl/filesystem.cxx
index fa36ed3..4698ed9 100644
--- a/libbutl/filesystem.cxx
+++ b/libbutl/filesystem.cxx
@@ -1453,9 +1453,11 @@ namespace butl
   {
     using error = pair<entry_type, system_error>;
 
+    const path& tp (rel ? target.relative (link.directory ()) : target);
+
     try
     {
-      mksymlink (rel ? target.relative (link.directory ()) : target, link);
+      mksymlink (tp, link);
       return entry_type::symlink;
     }
     catch (system_error& e)
@@ -1469,9 +1471,19 @@ namespace butl
         if (c == ENOSYS || // Not implemented.
             c == EPERM)    // Not supported by the filesystem(s).
         {
+          // Note that for hardlinking/copying we need to complete a relative
+          // target using the link directory.
+          //
+          const path& ctp (tp.relative () ? link.directory () / tp : tp);
+
           try
           {
-            mkhardlink (target, link);
+            // The target can be a symlink (or a symlink chain) with a
+            // relative target that, unless the (final) symlink and the
+            // hardlink are in the same directory, will result in a dangling
+            // link.
+            //
+            mkhardlink (followsymlink (ctp), link);
             return entry_type::other;
           }
           catch (system_error& e)
@@ -1485,7 +1497,7 @@ namespace butl
               {
                 try
                 {
-                  cpfile (target, link);
+                  cpfile (ctp, link);
                   return entry_type::regular;
                 }
                 catch (system_error& e)
@@ -2416,7 +2428,7 @@ namespace butl
     recursive_dir_iterator (recursive_dir_iterator&&) = default;
 
     // Return false if no more entries left. Otherwise save the next entry path
-    // and return true. The path is relative against the directory being
+    // and return true. The path is relative to the directory being
     // traversed and contains a trailing separator for sub-directories. Throw
     // std::system_error in case of a failure (insufficient permissions,
     // dangling symlink encountered, etc).
diff --git a/libbutl/filesystem.mxx b/libbutl/filesystem.mxx
index a445b70..94ed366 100644
--- a/libbutl/filesystem.mxx
+++ b/libbutl/filesystem.mxx
@@ -362,7 +362,9 @@ LIBBUTL_MODEXPORT namespace butl
   // no directories, only files), whichever is possible in that order. If
   // `relative` is true, then make the symlink target relative to the link
   // directory (note: it is the caller's responsibility to make sure this is
-  // possible).
+  // possible). Otherwise, assume a relative target to be relative to the
+  // link directory and complete it accordingly when create a hardlink or a
+  // copy.
   //
   // On success, return the type of entry created: `regular` for copy,
   // `symlink` for symlink, and `other` for hardlink. On failure, throw a