[gimp] Bug 794634 - CRITICAL when adding layers with Dissolve mode

[N/A <ell src gnome org>]

commit f49e4b426391daaa528e5c4a18c5911a566aec39
Author: Ell <ell_se yahoo com>
Date:   Fri Mar 23 14:39:31 2018 -0400

    Bug 794634 - CRITICAL when adding layers with Dissolve mode
    
    Fix a CRITICAL when calling gimp_layer_mode_get_format() with an
    AUTO composite space and a NULL preferred format, which is valid:
    it means the layer mode is composite-space agnostic (as DISSOLVE
    is), and that there's no preferred format.
    
    A NULL preferred format can occur during
    gimp_operation_layer_mode_prepare() if the layer's mode node is not
    yet attached anything through its "input" or "aux" pads, which is
    the case during the call to gimp_layer_update_mode_node() while
    constructing the layer's node in gimp_layer_get_node().

 app/operations/layer-modes/gimp-layer-modes.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/operations/layer-modes/gimp-layer-modes.c b/app/operations/layer-modes/gimp-layer-modes.c
index 3fb0c77..e26ac6f 100644
--- a/app/operations/layer-modes/gimp-layer-modes.c
+++ b/app/operations/layer-modes/gimp-layer-modes.c
@@ -1416,7 +1416,7 @@ gimp_layer_mode_get_format (GimpLayerMode        mode,
       /* compositing is color-space agnostic.  return a format that has a fast
        * conversion path to/from the preferred format.
        */
-      if (gimp_babl_format_get_linear (preferred_format))
+      if (! preferred_format || gimp_babl_format_get_linear (preferred_format))
         return babl_format ("RGBA float");
       else
         return babl_format ("R'G'B'A float");