(update_text_area): Avoid needless redraw of rightmost

glyph whose face is extended to the text area end.

2 files changed, 15 insertions, 3 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 2630efe73b7..df85b407911 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2006-02-23  YAMAMOTO Mitsuharu  <mituharu@math.s.chiba-u.ac.jp>
+
+        * dispnew.c (update_text_area): Avoid needless redraw of rightmost
+        glyph whose face is extended to the text area end.
+
 2006-02-22  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * window.c (Fwindow_list): Check `window' before doing XWINDOW.
diff --git a/src/dispnew.c b/src/dispnew.c
index 52d5b989800..f6ce8eb43f4 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -4358,10 +4358,14 @@ update_text_area (w, vpos)
       int overlapping_glyphs_p = current_row->contains_overlapping_glyphs_p;
       int desired_stop_pos = desired_row->used[TEXT_AREA];
 
-      /* If the desired row extends its face to the text area end,
+      /* If the desired row extends its face to the text area end, and
+         unless the current row also does so at the same position,
          make sure we write at least one glyph, so that the face
          extension actually takes place.  */
-      if (MATRIX_ROW_EXTENDS_FACE_P (desired_row))
+      if (MATRIX_ROW_EXTENDS_FACE_P (desired_row)
+          && (desired_stop_pos < current_row->used[TEXT_AREA]
+              || (desired_stop_pos == current_row->used[TEXT_AREA]
+                  && !MATRIX_ROW_EXTENDS_FACE_P (current_row))))
         --desired_stop_pos;
 
       stop = min (current_row->used[TEXT_AREA], desired_stop_pos);
@@ -4480,7 +4484,10 @@ update_text_area (w, vpos)
              has to be cleared, if and only if we did a write_glyphs
              above.  This is made sure by setting desired_stop_pos
              appropriately above.  */
-          xassert (i < desired_row->used[TEXT_AREA]);
+          xassert (i < desired_row->used[TEXT_AREA]
+                   || ((desired_row->used[TEXT_AREA]
+                        == current_row->used[TEXT_AREA])
+                       && MATRIX_ROW_EXTENDS_FACE_P (current_row)));
         }
       else if (MATRIX_ROW_EXTENDS_FACE_P (current_row))
         {