[Emacs-diffs] Changes to emacs/src/xdisp.c

[Richard M. Stallman]

Index: emacs/src/xdisp.c
diff -c emacs/src/xdisp.c:1.783 emacs/src/xdisp.c:1.784
*** emacs/src/xdisp.c:1.783     Sat Aug 31 06:16:40 2002
--- emacs/src/xdisp.c   Sun Sep  1 09:43:38 2002
***************
*** 8963,8968 ****
--- 8963,8970 ----
                judge_scroll_bars_hook (f);
  
              /* If fonts changed, display again.  */
+             /* ??? rms: I suspect it is a mistake to jump all the way
+                back to retry here.  It should just retry this frame.  */
              if (fonts_changed_p)
                goto retry;
  
***************
*** 10098,10104 ****
  
  
  /* Redisplay leaf window WINDOW.  JUST_THIS_ONE_P non-zero means only
!    selected_window is redisplayed.  */
  
  static void
  redisplay_window (window, just_this_one_p)
--- 10100,10110 ----
  
  
  /* Redisplay leaf window WINDOW.  JUST_THIS_ONE_P non-zero means only
!    selected_window is redisplayed.
! 
!    We can return without actually redisplaying the window if
!    fonts_changed_p is nonzero.  In that case, redisplay_internal will
!    retry.  */
  
  static void
  redisplay_window (window, just_this_one_p)
***************
*** 10305,10310 ****
--- 10311,10319 ----
    if (!NILP (w->force_start)
        || w->frozen_window_start_p)
      {
+       /* We set this later on if we have to adjust point.  */
+       int new_vpos = -1;
+ 
        w->force_start = Qnil;
        w->vscroll = 0;
        w->window_end_valid = Qnil;
***************
*** 10341,10347 ****
        {
          w->force_start = Qt;
          clear_glyph_matrix (w->desired_matrix);
!         goto finish_scroll_bars;
        }
  
        if (w->cursor.vpos < 0 && !w->frozen_window_start_p)
--- 10350,10356 ----
        {
          w->force_start = Qt;
          clear_glyph_matrix (w->desired_matrix);
!         goto need_larger_matrices;
        }
  
        if (w->cursor.vpos < 0 && !w->frozen_window_start_p)
***************
*** 10349,10360 ****
          /* If point does not appear, try to move point so it does
             appear. The desired matrix has been built above, so we
             can use it here.  */
!         int window_height;
          struct glyph_row *row;
  
-         window_height = window_box_height (w) / 2;
          row = MATRIX_FIRST_TEXT_ROW (w->desired_matrix);
!         while (MATRIX_ROW_BOTTOM_Y (row) < window_height)
            ++row;
  
          TEMP_SET_PT_BOTH (MATRIX_ROW_START_CHARPOS (row),
--- 10358,10381 ----
          /* If point does not appear, try to move point so it does
             appear. The desired matrix has been built above, so we
             can use it here.  */
!         new_vpos = window_box_height (w) / 2;
!       }
! 
!       if (!make_cursor_line_fully_visible (w))
!       {
!         /* Point does appear, but on a line partly visible at end of window.
!            Move it back to a fully-visible line.  */
!         new_vpos = window_box_height (w);
!       }
! 
!       /* If we need to move point for either of the above reasons,
!        now actually do it.  */
!       if (new_vpos >= 0)
!       {
          struct glyph_row *row;
  
          row = MATRIX_FIRST_TEXT_ROW (w->desired_matrix);
!         while (MATRIX_ROW_BOTTOM_Y (row) < new_vpos)
            ++row;
  
          TEMP_SET_PT_BOTH (MATRIX_ROW_START_CHARPOS (row),
***************
*** 10378,10422 ****
            }
        }
  
-       if (!make_cursor_line_fully_visible (w))
-       {
-         /* CVS rev. 1.761 had changed this to ``goto try_to_scroll''.
- 
-            The intention of the fix -- AFAIU -- was to ensure that 
-            the cursor didn't end up on a partially visible last (or
-            first?) line when scrolling.
- 
- 
-            But that change causes havoc when scrolling backwards and
-            a partially visible first (or last?) line is present when
-            we reach the top of the buffer.  In effect, the text
-            already in the window is repeated (each line is appended
-            to the same or another lines in the window)...
- 
-            I changed it back to ``goto need_larger_matrices'' which
-            in effect mean that we don't go through `try_scrolling'
-            when the cursor is already at the first line of the buffer,
-            and there is really only a few pixels [rather than lines]
-            to scroll backwards.  I guess move_it_by_lines etc. really
-            isn't the right device for doing that, ref. the code in
-            make_cursor_line_fully_visible which was also disabled by
-            CVS rev. 1.761.
- 
-            But how do we know that we are already on the top line of
-            the window showing the first line in the buffer, so that
-            scrolling really wont help here?
- 
-            I cannot find a simple fix for this (I tried various
-            approaches), but I prefer to an occasional partial line
-            rather than the visual messup, so I reverted this part of
-            the fix.
- 
-            Someone will need to look into this when time allows.
- 
-            -- 2002-08-22, Kim F. Storm  */
- 
-         goto need_larger_matrices;
-       }
  #if GLYPH_DEBUG
        debug_method_add (w, "forced window start");
  #endif
--- 10399,10404 ----
***************
*** 10435,10442 ****
--- 10417,10426 ----
        case CURSOR_MOVEMENT_SUCCESS:
          goto done;
  
+ #if 0  /* try_cursor_movement never returns this value.  */
        case CURSOR_MOVEMENT_NEED_LARGER_MATRICES:
          goto need_larger_matrices;
+ #endif
  
        case CURSOR_MOVEMENT_MUST_SCROLL:
          goto try_to_scroll;
***************
*** 10765,10770 ****
--- 10749,10758 ----
  #endif
      }
  
+   /* We go to this label, with fonts_changed_p nonzero,
+      if it is necessary to try again using larger glyph matrices.
+      We have to redeem the scroll bar even in this case,
+      because the loop in redisplay_internal expects that.  */
   need_larger_matrices:
    ;
   finish_scroll_bars: