[gimp/gimp-2-10] Issue #3718 - Large colorrc file causes lag when painting with a new color

[Ell <ell src gnome org>]

commit 8d15563f4cd7a66fd3f5601ba576cee9897c86e6
Author: Ell <ell_se yahoo com>
Date:   Wed Aug 7 18:32:19 2019 +0300

    Issue #3718 - Large colorrc file causes lag when painting with a new color
    
    In gimp_palette_mru_add(), if the added color doesn't match an
    existing color, don't look for two duplicate existing colors (which
    has quadratic complexity), since there shouldn't be any under
    normal circumstances (as we're not adding duplicates to begin
    with).
    
    (cherry picked from commit e60829767e0f7e2a1a7b17df2e2ea5d285365716)

 app/core/gimppalettemru.c | 53 ++++++++---------------------------------------
 1 file changed, 9 insertions(+), 44 deletions(-)
---
diff --git a/app/core/gimppalettemru.c b/app/core/gimppalettemru.c
index d67cef8674..7ca33ff991 100644
--- a/app/core/gimppalettemru.c
+++ b/app/core/gimppalettemru.c
@@ -187,9 +187,8 @@ void
 gimp_palette_mru_add (GimpPaletteMru *mru,
                       const GimpRGB  *color)
 {
-  GimpPalette      *palette;
-  GimpPaletteEntry *found = NULL;
-  GList            *list;
+  GimpPalette *palette;
+  GList       *list;
 
   g_return_if_fail (GIMP_IS_PALETTE_MRU (mru));
   g_return_if_fail (color != NULL);
@@ -205,50 +204,16 @@ gimp_palette_mru_add (GimpPaletteMru *mru,
 
       if (gimp_rgba_distance (&entry->color, color) < RGBA_EPSILON)
         {
-          found = entry;
-
-          goto doit;
-        }
-    }
-
-  /*  if not, are there two equal colors?  */
-  if (! found)
-    {
-      for (list = gimp_palette_get_colors (palette);
-           list;
-           list = g_list_next (list))
-        {
-          GimpPaletteEntry *entry = list->data;
-          GList            *list2;
+          gimp_palette_move_entry (palette, entry, 0);
 
-          for (list2 = g_list_next (list); list2; list2 = g_list_next (list2))
-            {
-              GimpPaletteEntry *entry2 = list2->data;
+          /*  Even though they are nearly the same color, let's make them
+           *  exactly equal.
+           */
+          gimp_palette_set_entry_color (palette, 0, color);
 
-              if (gimp_rgba_distance (&entry->color,
-                                      &entry2->color) < RGBA_EPSILON)
-                {
-                  found = entry2;
-
-                  goto doit;
-                }
-            }
+          return;
         }
     }
 
- doit:
-
-  if (found)
-    {
-      gimp_palette_move_entry (palette, found, 0);
-      /* Even though they are nearly the same color, let's make them exactly
-      * equal. */
-      gimp_palette_set_entry_color (palette,
-                                    0,
-                                    color);
-    }
-  else
-    {
-      gimp_palette_add_entry (palette, 0, _("History Color"), color);
-    }
+  gimp_palette_add_entry (palette, 0, _("History Color"), color);
 }