[gimp] app: fix undo when moving a group-layer child outside the group

[N/A <ell src gnome org>]

commit 577e17032abd3201b7eef6edac1a4f88c99f8728
Author: Ell <ell_se yahoo com>
Date:   Sun Apr 22 03:18:37 2018 -0400

    app: fix undo when moving a group-layer child outside the group
    
    In gimp_image_reorder_item(), call gimp_item_start/end_move()
    before/after reordering the item (and use an undo group, so that
    the resulting undo actions are grouped together with the reordering
    undo action,) so that if the item is a child of a group layer, and
    reordering moves it out of the group in a way that causes the
    group's mask to be resized, the mask will be properly restored when
    undoing the operation.

 app/core/core-enums.c |    2 ++
 app/core/core-enums.h |    1 +
 app/core/gimpimage.c  |   26 +++++++++++++++++++++-----
 3 files changed, 24 insertions(+), 5 deletions(-)
---
diff --git a/app/core/core-enums.c b/app/core/core-enums.c
index 2433381..355b298 100644
--- a/app/core/core-enums.c
+++ b/app/core/core-enums.c
@@ -770,6 +770,7 @@ gimp_undo_type_get_type (void)
     { GIMP_UNDO_GROUP_IMAGE_CROP, "GIMP_UNDO_GROUP_IMAGE_CROP", "group-image-crop" },
     { GIMP_UNDO_GROUP_IMAGE_CONVERT, "GIMP_UNDO_GROUP_IMAGE_CONVERT", "group-image-convert" },
     { GIMP_UNDO_GROUP_IMAGE_ITEM_REMOVE, "GIMP_UNDO_GROUP_IMAGE_ITEM_REMOVE", "group-image-item-remove" },
+    { GIMP_UNDO_GROUP_IMAGE_ITEM_REORDER, "GIMP_UNDO_GROUP_IMAGE_ITEM_REORDER", "group-image-item-reorder" },
     { GIMP_UNDO_GROUP_IMAGE_LAYERS_MERGE, "GIMP_UNDO_GROUP_IMAGE_LAYERS_MERGE", "group-image-layers-merge" },
     { GIMP_UNDO_GROUP_IMAGE_VECTORS_MERGE, "GIMP_UNDO_GROUP_IMAGE_VECTORS_MERGE", 
"group-image-vectors-merge" },
     { GIMP_UNDO_GROUP_IMAGE_QUICK_MASK, "GIMP_UNDO_GROUP_IMAGE_QUICK_MASK", "group-image-quick-mask" },
@@ -867,6 +868,7 @@ gimp_undo_type_get_type (void)
     { GIMP_UNDO_GROUP_IMAGE_CROP, NC_("undo-type", "Crop image"), NULL },
     { GIMP_UNDO_GROUP_IMAGE_CONVERT, NC_("undo-type", "Convert image"), NULL },
     { GIMP_UNDO_GROUP_IMAGE_ITEM_REMOVE, NC_("undo-type", "Remove item"), NULL },
+    { GIMP_UNDO_GROUP_IMAGE_ITEM_REORDER, NC_("undo-type", "Reorder item"), NULL },
     { GIMP_UNDO_GROUP_IMAGE_LAYERS_MERGE, NC_("undo-type", "Merge layers"), NULL },
     { GIMP_UNDO_GROUP_IMAGE_VECTORS_MERGE, NC_("undo-type", "Merge paths"), NULL },
     { GIMP_UNDO_GROUP_IMAGE_QUICK_MASK, NC_("undo-type", "Quick Mask"), NULL },
diff --git a/app/core/core-enums.h b/app/core/core-enums.h
index e0705d5..7cafdf3 100644
--- a/app/core/core-enums.h
+++ b/app/core/core-enums.h
@@ -361,6 +361,7 @@ typedef enum /*< pdb-skip >*/
   GIMP_UNDO_GROUP_IMAGE_CROP,         /*< desc="Crop image"                  >*/
   GIMP_UNDO_GROUP_IMAGE_CONVERT,      /*< desc="Convert image"               >*/
   GIMP_UNDO_GROUP_IMAGE_ITEM_REMOVE,  /*< desc="Remove item"                 >*/
+  GIMP_UNDO_GROUP_IMAGE_ITEM_REORDER, /*< desc="Reorder item"                >*/
   GIMP_UNDO_GROUP_IMAGE_LAYERS_MERGE, /*< desc="Merge layers"                >*/
   GIMP_UNDO_GROUP_IMAGE_VECTORS_MERGE,/*< desc="Merge paths"                 >*/
   GIMP_UNDO_GROUP_IMAGE_QUICK_MASK,   /*< desc="Quick Mask"                  >*/
diff --git a/app/core/gimpimage.c b/app/core/gimpimage.c
index 7176369..8508419 100644
--- a/app/core/gimpimage.c
+++ b/app/core/gimpimage.c
@@ -4155,6 +4155,7 @@ gimp_image_reorder_item (GimpImage   *image,
                          const gchar *undo_desc)
 {
   GimpItemTree *tree;
+  gboolean      result;
 
   g_return_val_if_fail (GIMP_IS_IMAGE (image), FALSE);
   g_return_val_if_fail (GIMP_IS_ITEM (item), FALSE);
@@ -4164,14 +4165,29 @@ gimp_image_reorder_item (GimpImage   *image,
 
   g_return_val_if_fail (tree != NULL, FALSE);
 
-  if (push_undo && ! undo_desc)
-    undo_desc = GIMP_ITEM_GET_CLASS (item)->reorder_desc;
+  if (push_undo)
+    {
+      if (! undo_desc)
+        undo_desc = GIMP_ITEM_GET_CLASS (item)->reorder_desc;
+
+      gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_IMAGE_ITEM_REORDER,
+                                   undo_desc);
+    }
+
+  gimp_item_start_move (item, push_undo);
 
   /*  item and new_parent are type-checked in GimpItemTree
    */
-  return gimp_item_tree_reorder_item (tree, item,
-                                      new_parent, new_index,
-                                      push_undo, undo_desc);
+  result = gimp_item_tree_reorder_item (tree, item,
+                                        new_parent, new_index,
+                                        push_undo, undo_desc);
+
+  gimp_item_end_move (item, push_undo);
+
+  if (push_undo)
+    gimp_image_undo_group_end (image);
+
+  return result;
 }
 
 gboolean