Convert relative installation directory path to absolute in build scripts

1 files changed, 21 insertions, 0 deletions

diff --git a/build.sh b/build.sh
index 9d83209..a1ba1cf 100755
--- a/build.sh
+++ b/build.sh
@@ -225,6 +225,12 @@ if test -n "$make"; then
   fi
 fi
 
+# If the installation directory is unspecified, then assume it is /usr/local.
+# Otherwise, if it is a relative path, then convert it to an absolute path,
+# unless the realpath program is not present on the system or doesn't
+# recognize any of the options we pass, in which case fail, advising to
+# specify an absolute installation directory.
+#
 if test -z "$idir"; then
   idir=/usr/local
   private=config.install.private=build2
@@ -235,6 +241,21 @@ if test -z "$idir"; then
   if test -z "$sudo"; then
     sudo="sudo"
   fi
+elif test -n "$(echo "$idir" | sed -n 's#^[^/].*$#true#p')"; then
+
+  if ! command -v realpath >/dev/null 2>&1; then
+    diag "error: unable to execute realpath: command not found"
+    diag "  info: specify absolute installation directory path"
+    exit 1
+  fi
+
+  # Don't resolve symlinks and allow non-existent path components.
+  #
+  if ! idir="$(realpath -s -m "$idir" 2>/dev/null)"; then
+    diag "error: realpath does not recognize -s -m"
+    diag "  info: specify absolute installation directory path"
+    exit 1
+  fi
 fi
 
 if test "$sudo" = false; then