[gimp] app: suspend layer-group size updates while loading XCF

[Ell <ell src gnome org>]

commit 63df5602a2cf3942db080c69c084cf70560f5efa
Author: Ell <ell_se yahoo com>
Date:   Sat Feb 22 12:41:47 2020 +0200

    app: suspend layer-group size updates while loading XCF
    
    In xcf_load_image(), suspend size updates for layer groups before
    adding their sublayers, to avoid unnecessary intermediary size
    updates.  Resume size updates in reverse order, so that nested
    groups are updated before their ancestors, after all layers have
    been loaded.

 app/xcf/xcf-load.c | 42 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)
---
diff --git a/app/xcf/xcf-load.c b/app/xcf/xcf-load.c
index 69f616bee0..28cfefe3c6 100644
--- a/app/xcf/xcf-load.c
+++ b/app/xcf/xcf-load.c
@@ -175,6 +175,7 @@ xcf_load_image (Gimp     *gimp,
   gint                n_broken_layers         = 0;
   gint                n_broken_channels       = 0;
   GList              *broken_paths            = NULL;
+  GList              *group_layers            = NULL;
   GList              *syms;
   GList              *iter;
 
@@ -513,6 +514,16 @@ xcf_load_image (Gimp     *gimp,
 
       xcf_progress_update (info);
 
+      /* suspend layer-group size updates */
+      if (GIMP_IS_GROUP_LAYER (layer))
+        {
+          GimpGroupLayer *group = GIMP_GROUP_LAYER (layer);
+
+          group_layers = g_list_prepend (group_layers, group);
+
+          gimp_group_layer_suspend_resize (group, FALSE);
+        }
+
       /* add the layer to the image if its not the floating selection */
       if (layer != info->floating_sel)
         {
@@ -566,6 +577,15 @@ xcf_load_image (Gimp     *gimp,
         goto error;
     }
 
+  /* resume layer-group size updates, in reverse order */
+  for (iter = group_layers; iter; iter = g_list_next (iter))
+    {
+      GimpGroupLayer *group = iter->data;
+
+      gimp_group_layer_resume_resize (group, FALSE);
+    }
+  g_clear_pointer (&group_layers, g_list_free);
+
   if (broken_paths)
     {
       g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
@@ -659,12 +679,17 @@ xcf_load_image (Gimp     *gimp,
   return image;
 
  error:
-  if (broken_paths)
-    g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
-
   if (num_successful_elements == 0)
     goto hard_error;
 
+  g_clear_pointer (&group_layers, g_list_free);
+
+  if (broken_paths)
+    {
+      g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
+      broken_paths = NULL;
+    }
+
   gimp_message_literal (gimp, G_OBJECT (info->progress), GIMP_MESSAGE_WARNING,
                         _("This XCF file is corrupt!  I have loaded as much "
                           "of it as I can, but it is incomplete."));
@@ -676,12 +701,19 @@ xcf_load_image (Gimp     *gimp,
   return image;
 
  hard_error:
+  g_clear_pointer (&group_layers, g_list_free);
+
+  if (broken_paths)
+    {
+      g_list_free_full (broken_paths, (GDestroyNotify) g_list_free);
+      broken_paths = NULL;
+    }
+
   g_set_error_literal (error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
                        _("This XCF file is corrupt!  I could not even "
                          "salvage any partial image data from it."));
 
-  if (image)
-    g_object_unref (image);
+  g_clear_object (&image);
 
   return NULL;
 }