(update_frame_line): If writing whole desired line,

don't clear to end of line if already at the end.

1 files changed, 21 insertions, 9 deletions

diff --git a/src/dispnew.c b/src/dispnew.c
index 599019152c0..87ad3de2e07 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -4781,31 +4781,31 @@ update_frame_line (frame, vpos)
   else
     reassert_line_highlight (desired_row->inverse_p, vpos);
 
+  /* Current row not enabled means it has unknown contents.  We must
+     write the whole desired line in that case.  */
   must_write_whole_line_p = !current_row->enabled_p;
   if (must_write_whole_line_p)
     {
-      /* A line that is not enabled is empty.  */
       obody = 0;
       olen = 0;
     }
   else
     {
-      /* A line not empty in the current matrix.  */
       obody = MATRIX_ROW_GLYPH_START (current_matrix, vpos);
       olen = current_row->used[TEXT_AREA];
       
       if (! current_row->inverse_p)
         {
-          /* Ignore trailing spaces.  */
+          /* Ignore trailing spaces, if we can.  */
           if (!must_write_spaces)
             while (olen > 0 && CHAR_GLYPH_SPACE_P (obody[olen-1]))
               olen--;
         }
       else
         {
-          /* For an inverse-video line, remember we gave it spaces all
-             the way to the frame edge so that the reverse video
-             extends all the way across.  */
+          /* For an inverse-video line, make sure it's filled with
+             spaces all the way to the frame edge so that the reverse
+             video extends all the way across.  */
           while (olen < FRAME_WIDTH (frame) - 1)
             obody[olen++] = space_glyph;
         }
@@ -4829,15 +4829,27 @@ update_frame_line (frame, vpos)
   /* If display line has unknown contents, write the whole line.  */
   if (must_write_whole_line_p)
     {
+      /* Ignore spaces at the end, if we can.  */
       if (!must_write_spaces)
         while (nlen > 0 && CHAR_GLYPH_SPACE_P (nbody[nlen - 1]))
           --nlen;
 
-      cursor_to (vpos, 0);
+      /* Write the contents of the desired line.  */
       if (nlen)
-        write_glyphs (nbody, nlen);
+        {
+          cursor_to (vpos, 0);
+          write_glyphs (nbody, nlen);
+        }
       
-      clear_end_of_line (FRAME_WINDOW_WIDTH (frame));
+      /* Don't call clear_end_of_line if we already wrote the whole
+         line.  The cursor will not be at the right margin in that
+         case but in the line below.  */
+      if (nlen < FRAME_WINDOW_WIDTH (frame))
+        {
+          cursor_to (vpos, nlen);
+          clear_end_of_line (FRAME_WINDOW_WIDTH (frame));
+        }
+
       make_current (desired_matrix, current_matrix, vpos);
       return;
     }