2 files changed, 21 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 484f1c50d56..0e880dbc0b6 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
 2000-10-30  Gerd Moellmann  <gerd@gnu.org>
 
+        * xterm.c (x_alloc_nearest_color): If allocation succeeds, and
+        we have a color cache, check that the cached color equals the
+        allocated color.  If not, clear the color cache.
+
         * window.c (displayed_window_lines): Change buffers if necessary.
         Fix computation of displayed lines.
 
diff --git a/src/xterm.c b/src/xterm.c
index a55117ba8dc..556611286bc 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -3412,6 +3412,23 @@ x_alloc_nearest_color (f, cmap, color)
       color->blue  = cells[nearest].blue;
       rc = XAllocColor (display, cmap, color);
     }
+  else
+    {
+      /* If allocation succeeded, and the allocated pixel color is not
+         equal to a cached pixel color recorded earlier, there was a
+         change in the colormap, so clear the color cache.  */
+      struct x_display_info *dpyinfo = FRAME_X_DISPLAY_INFO (f);
+      XColor *cached_color;
+      
+      if (dpyinfo->color_cells
+          && (cached_color = &dpyinfo->color_cells[color->pixel],
+              cached_color->pixel != color->pixel))
+        {
+          xfree (dpyinfo->color_cells);
+          dpyinfo->color_cells = NULL;
+          dpyinfo->ncolor_cells = 0;
+        }
+    }
 
 #ifdef DEBUG_X_COLORS
   if (rc)