[gimp/gimp-2-10] Issue 2052 - Crash when using the flip tool

[Ell <ell src gnome org>]

commit 0e3084a9d14e8d75013ef6543e699fca716d46a9
Author: Ell <ell_se yahoo com>
Date:   Mon Aug 20 04:18:22 2018 -0400

    Issue 2052 - Crash when using the flip tool
    
    In gimp_transform_tool_transform(), use "active_item", instead of
    "tool->drawable", when cutting/pasting the selected portion of a
    layer for transformation.  The latter is a remnant of the old
    transform-tool code, and is not guaranteed to be correspond to the
    correct drawable, or even to a valid drawable (i.e., it can
    potentially produce wrong results, or segfault.)
    
    (cherry picked from commit 9420805525b086f47dea52b9c42bac2936361835)

 app/tools/gimptransformtool.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/app/tools/gimptransformtool.c b/app/tools/gimptransformtool.c
index e09d9eac1b..cf8cb328b7 100644
--- a/app/tools/gimptransformtool.c
+++ b/app/tools/gimptransformtool.c
@@ -459,10 +459,10 @@ gimp_transform_tool_transform (GimpTransformTool *tr_tool,
   switch (options->type)
     {
     case GIMP_TRANSFORM_TYPE_LAYER:
-      if (! gimp_viewable_get_children (GIMP_VIEWABLE (tool->drawable)) &&
+      if (! gimp_viewable_get_children (GIMP_VIEWABLE (active_item)) &&
           ! gimp_channel_is_empty (gimp_image_get_mask (image)))
         {
-          orig_buffer = gimp_drawable_transform_cut (tool->drawable,
+          orig_buffer = gimp_drawable_transform_cut (GIMP_DRAWABLE (active_item),
                                                      context,
                                                      &orig_offset_x,
                                                      &orig_offset_y,
@@ -500,7 +500,7 @@ gimp_transform_tool_transform (GimpTransformTool *tr_tool,
           /*  paste the new transformed image to the image...also implement
            *  undo...
            */
-          gimp_drawable_transform_paste (tool->drawable,
+          gimp_drawable_transform_paste (GIMP_DRAWABLE (active_item),
                                          new_buffer, buffer_profile,
                                          new_offset_x, new_offset_y,
                                          new_layer);