[gimp] BUG 793634: CRITICAL loading psd file with disabled layer mask

[Jehan Pagès <jehanp src gnome org>]

commit 87525c89111639b7e7d441532eca4eb9414877fd
Author: Massimo Valentini <mvalentini src gnome org>
Date:   Tue Feb 20 11:03:21 2018 +0100

    BUG 793634: CRITICAL loading psd file with disabled layer mask
    
    Similarly to other layer setter functions, don't push undo
    steps if the layer is not yet attached

 app/core/gimplayer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/app/core/gimplayer.c b/app/core/gimplayer.c
index f0d453b..8f52473 100644
--- a/app/core/gimplayer.c
+++ b/app/core/gimplayer.c
@@ -2116,7 +2116,7 @@ gimp_layer_set_apply_mask (GimpLayer *layer,
     {
       GimpImage *image = gimp_item_get_image (GIMP_ITEM (layer));
 
-      if (push_undo)
+      if (push_undo && gimp_item_is_attached (GIMP_ITEM (layer)))
         gimp_image_undo_push_layer_mask_apply (image,
                                                apply ?
                                                C_("undo-type", "Enable Layer Mask") :