[gnome-screenshot/gnome-3-4] Return NULL default screenshot dir on absence.

[Theppitak Karoonboonyanan <tkaroonb src gnome org>]

commit e114d4de0b77946f67a904b83c4dc284340ce297
Author: Theppitak <thep linux thai net>
Date:   Sun Aug 12 20:56:36 2012 +0700

    Return NULL default screenshot dir on absence.
    
    When XDG_PICTURES_DIR is not set, get_default_screenshot_dir() should return
    NULL, not "file://".
    
    https://bugzilla.gnome.org/show_bug.cgi?id=681659

 src/screenshot-filename-builder.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/src/screenshot-filename-builder.c b/src/screenshot-filename-builder.c
index e143694..8b6d851 100644
--- a/src/screenshot-filename-builder.c
+++ b/src/screenshot-filename-builder.c
@@ -86,9 +86,14 @@ get_fallback_screenshot_dir (void)
 static gchar *
 get_default_screenshot_dir (void)
 {
+  const gchar *pictures_dir;
   gchar *shot_dir;
 
-  shot_dir = g_strconcat ("file://", g_get_user_special_dir (G_USER_DIRECTORY_PICTURES), NULL);
+  pictures_dir = g_get_user_special_dir (G_USER_DIRECTORY_PICTURES);
+  if (pictures_dir == NULL)
+    return NULL;
+
+  shot_dir = g_strconcat ("file://", pictures_dir, NULL);
 
   return shot_dir;
 }