[gnome-builder] makecache: ensure we always pass a subdir string.

[Christian Hergert <chergert src gnome org>]

commit 8f0105deb45b836b6d9e65e2b671cc651fad6af2
Author: Christian Hergert <christian hergert me>
Date:   Thu Apr 30 13:17:14 2015 -0700

    makecache: ensure we always pass a subdir string.
    
    We require it so that these other methods can be a bit more simple. This
    just makes sure we adhere to that contract.

 libide/autotools/ide-makecache.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libide/autotools/ide-makecache.c b/libide/autotools/ide-makecache.c
index 9053f05..7dfbe17 100644
--- a/libide/autotools/ide-makecache.c
+++ b/libide/autotools/ide-makecache.c
@@ -997,7 +997,7 @@ ide_makecache_get_file_flags_worker (GTask        *task,
         {
           const gchar *line = lines [i];
 
-          if ((ret = ide_makecache_parse_line (self, line, relpath, subdir)))
+          if ((ret = ide_makecache_parse_line (self, line, relpath, subdir ?: ".")))
             break;
         }