(insert_left_trunc_glyphs): Overwrite padding glyphs by

truncation glyphs.
(display_line): Optimize for wide characters.
(display_string): Don't try to display a multi-column charaters
partially.  On ttys, produce more than one truncation glyph for
multi-column characters that don't fit on the line.

1 files changed, 37 insertions, 12 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 4a3abe5bc13..a2496dd2dbb 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -11695,14 +11695,16 @@ insert_left_trunc_glyphs (it)
   while (from < end)
     *to++ = *from++;
 
-  /* There may be padding glyphs left over.  Remove them.  */
-  from = to;
-  while (from < toend && CHAR_GLYPH_PADDING_P (*from))
-    ++from;
-  while (from < toend)
-    *to++ = *from++;
+  /* There may be padding glyphs left over.  Overwrite them too.  */
+  while (to < toend && CHAR_GLYPH_PADDING_P (*to))
+    {
+      from = truncate_it.glyph_row->glyphs[TEXT_AREA];
+      while (from < end)
+        *to++ = *from++;
+    }
 
-  it->glyph_row->used[TEXT_AREA] = to - it->glyph_row->glyphs[TEXT_AREA];
+  if (to > toend)
+    it->glyph_row->used[TEXT_AREA] = to - it->glyph_row->glyphs[TEXT_AREA];
 }
 
 
@@ -12188,10 +12190,13 @@ display_line (it)
       hpos_before = it->hpos;
       x_before = x;
           
-      if (nglyphs == 1
+      if ((nglyphs == 1
+           /* A wide multibyte character produces multiple glyphs on
+              tty window  .*/
+           || !SINGLE_BYTE_CHAR_P (it->c))
           && it->current_x < it->last_visible_x)
         {
-          ++it->hpos;
+          it->hpos += nglyphs;
           row->ascent = max (row->ascent, it->max_ascent);
           row->height = max (row->height, it->max_ascent + it->max_descent);
           row->phys_ascent = max (row->phys_ascent, it->max_phys_ascent);
@@ -13715,8 +13720,17 @@ display_string (string, lisp_string, face_string, face_string_pos,
               && x + glyph->pixel_width > max_x)
             {
               /* End of continued line or max_x reached.  */
-              it->glyph_row->used[TEXT_AREA] = n_glyphs_before + i;
-              it->current_x = x;
+              if (CHAR_GLYPH_PADDING_P (*glyph))
+                {
+                  /* A wide character is unbreakable.  */
+                  it->glyph_row->used[TEXT_AREA] = n_glyphs_before;
+                  it->current_x = x_before;
+                }
+              else
+                {
+                  it->glyph_row->used[TEXT_AREA] = n_glyphs_before + i;
+                  it->current_x = x;
+                }
               break;
             }
           else if (x + glyph->pixel_width > it->first_visible_x)
@@ -13764,7 +13778,18 @@ display_string (string, lisp_string, face_string, face_string_pos,
           if (IT_CHARPOS (*it) < it->string_nchars)
             {
               if (!FRAME_WINDOW_P (it->f))
-                produce_special_glyphs (it, IT_TRUNCATION);
+                {
+                  int i, n;
+
+                  for (i = row->used[TEXT_AREA] - 1; i > 0; --i)
+                    if (!CHAR_GLYPH_PADDING_P (row->glyphs[TEXT_AREA][i]))
+                      break;
+                  for (n = row->used[TEXT_AREA]; i < n; ++i)
+                    {
+                      row->used[TEXT_AREA] = i;
+                      produce_special_glyphs (it, IT_TRUNCATION);
+                    }
+                }
               it->glyph_row->truncated_on_right_p = 1;
             }
           break;