[gimp] app: use BG fill in gimp_drawable_fill() if the drawable has no alpha

[Michael Natterer <mitch src gnome org>]

commit a06f7e78f10a43a63a524da4c4720499f8fd977b
Author: Michael Natterer <mitch gimp org>
Date:   Sun Oct 9 21:30:43 2016 +0200

    app: use BG fill in gimp_drawable_fill() if the drawable has no alpha

 app/core/gimpdrawable-fill.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/app/core/gimpdrawable-fill.c b/app/core/gimpdrawable-fill.c
index 0907328..3d4caad 100644
--- a/app/core/gimpdrawable-fill.c
+++ b/app/core/gimpdrawable-fill.c
@@ -59,6 +59,12 @@ gimp_drawable_fill (GimpDrawable *drawable,
   g_return_if_fail (GIMP_IS_DRAWABLE (drawable));
   g_return_if_fail (GIMP_IS_CONTEXT (context));
 
+  if (fill_type == GIMP_FILL_TRANSPARENT &&
+      ! gimp_drawable_has_alpha (drawable))
+    {
+      fill_type = GIMP_FILL_BACKGROUND;
+    }
+
   if (! gimp_get_fill_params (context, fill_type, &color, &pattern, NULL))
     return;