Fix display artifacts from ns_dumpglyphs_stretch (Bug#8470).

* src/nsterm.m (ns_dumpglyphs_stretch): Avoid overwriting left fringe
or scroll bar.

2 files changed, 18 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 2bd3cf8ec35..3f9c098b99a 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -9,6 +9,9 @@
         (EmacsTooltip -init): Remove bezels and add shadows to
         tooltip windows.
 
+        * nsterm.m (ns_dumpglyphs_stretch): Avoid overwriting left fringe
+        or scroll bar (Bug#8470).
+
 2011-07-28  Alp Aker  <alp.tekin.aker@gmail.com>
 
         Implement strike-through and overline on NextStep (Bug#8863).
diff --git a/src/nsterm.m b/src/nsterm.m
index e9e7dcc0804..d4b1a3f8473 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -3110,12 +3110,24 @@ ns_dumpglyphs_stretch (struct glyph_string *s)
         {
           if (!s->row->full_width_p)
             {
+              int overrun, leftoverrun;
+
               /* truncate to avoid overwriting fringe and/or scrollbar */
-              int overrun = max (0, (s->x + s->background_width)
-                                  - (WINDOW_BOX_RIGHT_EDGE_X (s->w)
-                                    - WINDOW_RIGHT_FRINGE_WIDTH (s->w)));
+              overrun = max (0, (s->x + s->background_width)
+                             - (WINDOW_BOX_RIGHT_EDGE_X (s->w)
+                                - WINDOW_RIGHT_FRINGE_WIDTH (s->w)));
               r[i].size.width -= overrun;
 
+              /* truncate to avoid overwriting to left of the window box */
+              leftoverrun = (WINDOW_BOX_LEFT_EDGE_X (s->w)
+                             + WINDOW_LEFT_FRINGE_WIDTH (s->w)) - s->x;
+
+              if (leftoverrun > 0)
+                {
+                  r[i].origin.x += leftoverrun;
+                  r[i].size.width -= leftoverrun;
+                }
+
               /* XXX: Try to work between problem where a stretch glyph on
                  a partially-visible bottom row will clear part of the
                  modeline, and another where list-buffers headers and similar