[gnome-builder] flatpak: set branch to NULL if unspecified

[Christian Hergert <chergert src gnome org>]

commit 73195093413d544d8a3167c2aa9022f8d5f9345c
Author: Christian Hergert <chergert redhat com>
Date:   Thu Mar 14 10:44:41 2019 -0700

    flatpak: set branch to NULL if unspecified
    
    We should not pass "" for the branch if it was not specified,
    instead pass NULL for easier comparisons elsewhere.

 src/plugins/flatpak/gbp-flatpak-util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/plugins/flatpak/gbp-flatpak-util.c b/src/plugins/flatpak/gbp-flatpak-util.c
index ffee1fee4..4b60733d5 100644
--- a/src/plugins/flatpak/gbp-flatpak-util.c
+++ b/src/plugins/flatpak/gbp-flatpak-util.c
@@ -122,7 +122,7 @@ gbp_flatpak_split_id (const gchar  *str,
 
   if (parts[i] != NULL)
     {
-      if (branch != NULL)
+      if (branch != NULL && !ide_str_empty0 (parts[i]))
         *branch = g_strdup (parts[i]);
     }