From 036510d19122702627192cec085612b87c79fb2b Mon Sep 17 00:00:00 2001
From: Jehan <jehan@girinstud.io>
Date: Mon, 9 Jan 2023 17:59:55 +0100
Subject: [PATCH] app: when arranging an item and an ancestor item, drop the
 descendant.

Trying to arranging both doesn't make sense and only end up in weird result. If
both the parent (layer group) and one or several child items are selected, just
arrange the parent.
---
 app/core/gimpimage-arrange.c | 46 +++++++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/app/core/gimpimage-arrange.c b/app/core/gimpimage-arrange.c
index 0a82212152..4aeb7bc001 100644
--- a/app/core/gimpimage-arrange.c
+++ b/app/core/gimpimage-arrange.c
@@ -36,7 +36,6 @@
 #include "gimp-intl.h"
 
 
-static GList * sort_by_offset  (GList             *list);
 static void    compute_offsets (GList             *list,
                                 gboolean           use_x_offset,
                                 gdouble            align_x,
@@ -89,11 +88,32 @@ gimp_image_arrange_objects (GimpImage         *image,
   gboolean do_x             = FALSE;
   gboolean do_y             = FALSE;
   gint     z0               = 0;
-  GList   *object_list;
+  GList   *object_list      = NULL;
 
   g_return_if_fail (GIMP_IS_IMAGE (image));
   g_return_if_fail (G_IS_OBJECT (reference) || reference == NULL);
 
+  /* Create the base list, removing any item which has one of its ancestor also
+   * in the list (in such case, we only rearrange the ancestor item.
+   */
+  for (GList *iter = list; iter; iter = iter->next)
+    {
+      GList *iter2 = NULL;
+
+      if (GIMP_IS_ITEM (iter->data))
+        {
+          for (iter2 = list; iter2; iter2 = iter2->next)
+            {
+              if (GIMP_IS_ITEM (iter->data) &&
+                  gimp_viewable_is_ancestor (iter2->data, iter->data))
+                break;
+            }
+        }
+
+      if (iter2 == NULL)
+        object_list = g_list_prepend (object_list, iter->data);
+    }
+
   /* get offsets used for sorting */
   switch (reference_alignment)
     {
@@ -118,7 +138,7 @@ gimp_image_arrange_objects (GimpImage         *image,
 
       /* order horizontally for horizontal arrangement */
     case GIMP_ARRANGE_HFILL:
-      if (g_list_length (list) <= 2)
+      if (g_list_length (object_list) <= 2)
         return;
       use_obj_x_offset = TRUE;
       use_ref_x_offset = TRUE;
@@ -143,7 +163,7 @@ gimp_image_arrange_objects (GimpImage         *image,
 
       /* order vertically for vertical arrangement */
     case GIMP_ARRANGE_VFILL:
-      if (g_list_length (list) <= 2)
+      if (g_list_length (object_list) <= 2)
         return;
       do_y = TRUE;
       break;
@@ -152,7 +172,7 @@ gimp_image_arrange_objects (GimpImage         *image,
       use_obj_x_offset = TRUE;
       do_x             = TRUE;
     case GIMP_DISTRIBUTE_EVEN_VERTICAL_GAP:
-      if (g_list_length (list) <= 2)
+      if (g_list_length (object_list) <= 2)
         return;
 
       if (! do_x)
@@ -166,13 +186,13 @@ gimp_image_arrange_objects (GimpImage         *image,
       g_return_if_reached ();
     }
   /* get offsets used for sorting */
-  compute_offsets (list, use_obj_x_offset, align_x, align_y, align_contents);
+  compute_offsets (object_list, use_obj_x_offset, align_x, align_y, align_contents);
 
-  /* Sort. */
-  object_list = sort_by_offset (list);
+  /* Sort by offset. */
+  object_list = g_list_sort (object_list, offset_compare);
 
   /* now get offsets used for aligning */
-  compute_offsets (list, use_obj_x_offset, align_x, align_y, align_contents);
+  compute_offsets (object_list, use_obj_x_offset, align_x, align_y, align_contents);
 
   if (object_list)
     {
@@ -319,14 +339,6 @@ gimp_image_arrange_objects (GimpImage         *image,
   g_list_free (object_list);
 }
 
-static GList *
-sort_by_offset (GList *list)
-{
-  return g_list_sort (g_list_copy (list),
-                      offset_compare);
-
-}
-
 static gint
 offset_compare (gconstpointer a,
                 gconstpointer b)