(try_window_reusing_current_matrix): Use

row_containing_pos.
(row_containing_pos): Take additional argument DY.  Treat
rows ending in middle of char differently.
(display_line): Handle tabs on window systems differently.

1 files changed, 36 insertions, 44 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 14413ca8f45..45b179a6ac6 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -10705,26 +10705,11 @@ try_window_reusing_current_matrix (w)
               int dy = it.current_y - first_row_y;
               
               row = MATRIX_FIRST_TEXT_ROW (w->current_matrix);
-              while (MATRIX_ROW_DISPLAYS_TEXT_P (row))
-                {
-                  if (PT >= MATRIX_ROW_START_CHARPOS (row)
-                      && PT < MATRIX_ROW_END_CHARPOS (row))
-                    {
-                      set_cursor_from_row (w, row, w->current_matrix, 0, 0,
-                                           dy, nrows_scrolled);
-                      break;
-                    }
-                  
-                  if (MATRIX_ROW_BOTTOM_Y (row) + dy >= it.last_visible_y)
-                    break;
-                  
-                  ++row;
-                }
-              
-              /* Give up if point was not found.  This shouldn't
-                 happen often; not more often than with try_window
-                 itself.  */
-              if (w->cursor.vpos < 0)
+              row = row_containing_pos (w, PT, row, NULL, dy);
+              if (row)
+                set_cursor_from_row (w, row, w->current_matrix, 0, 0,
+                                     dy, nrows_scrolled);
+              else
                 {
                   clear_glyph_matrix (w->desired_matrix);
                   return 0;
@@ -11200,10 +11185,11 @@ sync_frame_with_window_matrix_rows (w)
    containing CHARPOS or null.  */
 
 struct glyph_row *
-row_containing_pos (w, charpos, start, end)
+row_containing_pos (w, charpos, start, end, dy)
      struct window *w;
      int charpos;
      struct glyph_row *start, *end;
+     int dy;
 {
   struct glyph_row *row = start;
   int last_y;
@@ -11215,18 +11201,18 @@ row_containing_pos (w, charpos, start, end)
   if ((end && row >= end) || !row->enabled_p)
     return NULL;
   
-  last_y = window_text_bottom_y (w);
+  last_y = window_text_bottom_y (w) - dy;
       
   while ((end == NULL || row < end)
+         && MATRIX_ROW_BOTTOM_Y (row) < last_y
          && (MATRIX_ROW_END_CHARPOS (row) < charpos
-             /* The end position of a row equals the start
-                position of the next row.  If CHARPOS is there, we
-                would rather display it in the next line, except
-                when this line ends in ZV.  */
              || (MATRIX_ROW_END_CHARPOS (row) == charpos
-                 && (MATRIX_ROW_ENDS_IN_MIDDLE_OF_CHAR_P (row)
-                     || !row->ends_at_zv_p)))
-         && MATRIX_ROW_BOTTOM_Y (row) < last_y)
+                 /* The end position of a row equals the start
+                    position of the next row.  If CHARPOS is there, we
+                    would rather display it in the next line, except
+                    when this line ends in ZV.  */
+                 && !row->ends_at_zv_p
+                 && !MATRIX_ROW_ENDS_IN_MIDDLE_OF_CHAR_P (row))))
     ++row;
       
   /* Give up if CHARPOS not found.  */
@@ -11435,7 +11421,7 @@ try_window_id (w)
             }
       
           /* Set the cursor.  */
-          row = row_containing_pos (w, PT, r0, NULL);
+          row = row_containing_pos (w, PT, r0, NULL, 0);
           set_cursor_from_row (w, row, current_matrix, 0, 0, 0, 0);
           return 1;
         }
@@ -11473,7 +11459,7 @@ try_window_id (w)
             = Z_BYTE - MATRIX_ROW_END_BYTEPOS (row);
 
           /* Set the cursor.  */
-          row = row_containing_pos (w, PT, r0, NULL);
+          row = row_containing_pos (w, PT, r0, NULL, 0);
           set_cursor_from_row (w, row, current_matrix, 0, 0, 0, 0);
           return 2;
         }
@@ -11672,7 +11658,7 @@ try_window_id (w)
         {
           row = row_containing_pos (w, PT,
                                     MATRIX_FIRST_TEXT_ROW (w->current_matrix),
-                                    last_unchanged_at_beg_row + 1);
+                                    last_unchanged_at_beg_row + 1, 0);
           if (row)
             set_cursor_from_row (w, row, w->current_matrix, 0, 0, 0, 0);
         }
@@ -11681,7 +11667,7 @@ try_window_id (w)
       else if (first_unchanged_at_end_row)
         {
           row = row_containing_pos (w, PT - delta,
-                                    first_unchanged_at_end_row, NULL);
+                                    first_unchanged_at_end_row, NULL, 0);
           if (row)
             set_cursor_from_row (w, row, w->current_matrix, delta,
                                  delta_bytes, dy, dvpos);
@@ -12945,11 +12931,24 @@ display_line (it)
                       it->max_phys_ascent = phys_ascent;
                       it->max_phys_descent = phys_descent;
                     }
+                  else if (it->c == '\t' && FRAME_WINDOW_P (it->f))
+                    {
+                      /* A TAB that extends past the right edge of the
+                         window.  This produces a single glyph on
+                         window system frames.  We leave the glyph in
+                         this row and let it fill the row, but don't
+                         consume the TAB.  */
+                      it->continuation_lines_width += it->last_visible_x;
+                      row->ends_in_middle_of_char_p = 1;
+                      row->continued_p = 1;
+                      glyph->pixel_width = it->last_visible_x - x;
+                      it->starts_in_middle_of_char_p = 1;
+                    }
                   else
                     {
-                      /* Display element draws past the right edge of
-                         the window.  Restore positions to values
-                         before the element.  */
+                      /* Something other than a TAB that draws past
+                         the right edge of the window.  Restore
+                         positions to values before the element.  */
                       row->used[TEXT_AREA] = n_glyphs_before + i;
                   
                       /* Display continuation glyphs.  */
@@ -12957,14 +12956,7 @@ display_line (it)
                         produce_special_glyphs (it, IT_CONTINUATION);
                       row->continued_p = 1;
 
-                      /* A TAB takes us to the right edge of the window.  */
-                      if (it->c == '\t')
-                        {
-                          it->continuation_lines_width += it->last_visible_x;
-                          row->ends_in_middle_of_char_p = 1;
-                        }
-                      else
-                        it->continuation_lines_width += x;
+                      it->continuation_lines_width += x;
                       
                       if (nglyphs > 1 && i > 0)
                         {