Don't strip $libdir from LOAD command

petere · petere · commit f777d773878d · 2025-06-04T11:38:12.000+02:00
Commit 4f7f7b0 implemented the extension_control_path GUC, and to make it work it was decided that we should strip the $libdir/ on module_pathname from .control files, so that extensions don't need to worry about this change. This strip logic was implemented on expand_dynamic_library_name() which works fine when executing the SQL functions from extensions, but this function is also called when the LOAD command is executed, and since the user may explicitly pass the $libdir prefix on LOAD parameter, we should not strip in this case. This commit fixes this issue by moving the strip logic from expand_dynamic_library_name() to load_external_function() that is called when the running the SQL script from extensions. Reported-by: Evan Si <evsi@amazon.com> Author: Matheus Alcantara <matheusssilv97@gmail.com> Reviewed-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Rahila Syed <rahilasyed90@gmail.com> Bug: #18920 Discussion: https://www.postgresql.org/message-id/flat/18920-b350b1c0a30af006%40postgresql.org
diff --git a/src/backend/utils/fmgr/dfmgr.c b/src/backend/utils/fmgr/dfmgr.c
@@ -99,6 +99,14 @@ load_external_function(const char *filename, const char *funcname,
 	void	   *lib_handle;
 	void	   *retval;
 
+	/*
+	 * If the value starts with "$libdir/", strip that.  This is because many
+	 * extensions have hardcoded '$libdir/foo' as their library name, which
+	 * prevents using the path.
+	 */
+	if (strncmp(filename, "$libdir/", 8) == 0)
+		filename += 8;
+
 	/* Expand the possibly-abbreviated filename to an exact path name */
 	fullname = expand_dynamic_library_name(filename);
 
@@ -456,14 +464,6 @@ expand_dynamic_library_name(const char *name)
 
 	Assert(name);
 
-	/*
-	 * If the value starts with "$libdir/", strip that.  This is because many
-	 * extensions have hardcoded '$libdir/foo' as their library name, which
-	 * prevents using the path.
-	 */
-	if (strncmp(name, "$libdir/", 8) == 0)
-		name += 8;
-
 	have_slash = (first_dir_separator(name) != NULL);
 
 	if (!have_slash)
