path: add mp_find_config_file and reorganize some of the code

Add `mp_find_config_file` to search different known paths and use that in
ass_mp to look for the fontconfig configuration file.

Some incidental changes spawned by this feature where:

 * Buffer allocation for the strings containing the paths is now performed
   with talloc. All of the allocations are done on a NULL context, but it still
   improves readability of the code.
 * Move the OSX function for lookup inside of a bundle: this code path was
   currently not used by the bundle generated with `make osxbundle`. The plan
   is to use it again in a future commit to get a fontconfig config file.

1 files changed, 11 insertions, 1 deletions

diff --git a/core/path.h b/core/path.h
index 0c7dbcca41..3711be44b9 100644
--- a/core/path.h
+++ b/core/path.h
@@ -24,7 +24,17 @@
 #include <stdbool.h>
 #include "core/bstr.h"
 
-char *get_path(const char *filename);
+
+// Search for the input filename in several paths. These include user and global
+// config locations by default. Some platforms may implement additional platform
+// related lookups (i.e.: OSX inside an application bundle).
+char *mp_find_config_file(const char *filename);
+
+// Search for the input filename in the global configuration location.
+char *mp_find_global_config_file(const char *filename);
+
+// Search for the input filename in the user configuration location.
+char *mp_find_user_config_file(const char *filename);
 
 // Return pointer to filename part of path