[Emacs-diffs] /srv/bzr/emacs/trunk r100475: Fix cursor motion in bidi-reordered continued lines.

[Eli Zaretskii]

------------------------------------------------------------
revno: 100475 [merge]
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Sat 2010-05-29 15:51:01 +0300
message:
  Fix cursor motion in bidi-reordered continued lines.
  
   xdisp.c (try_cursor_movement): Backup to non-continuation line
   only after finding point's row.  Fix the logic.  Rewrite the loop
   over continuation lines in bidi-reordered buffers.  Return
   CURSOR_MOVEMENT_MUST_SCROLL upon failure to find a suitable row,
   rather than CURSOR_MOVEMENT_CANNOT_BE_USED.
modified:
  src/ChangeLog
  src/xdisp.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2010-05-28 14:57:11 +0000
+++ b/src/ChangeLog     2010-05-29 12:51:01 +0000
@@ -1,3 +1,12 @@
+2010-05-29  Eli Zaretskii  <address@hidden>
+
+       Fix cursor motion in bidi-reordered continued lines.
+       * xdisp.c (try_cursor_movement): Backup to non-continuation line
+       only after finding point's row.  Fix the logic.  Rewrite the loop
+       over continuation lines in bidi-reordered buffers.  Return
+       CURSOR_MOVEMENT_MUST_SCROLL upon failure to find a suitable row,
+       rather than CURSOR_MOVEMENT_CANNOT_BE_USED.
+
 2010-05-28  Michael Albinus  <address@hidden>
 
        * fileio.c (Fdelete_file): Pass TRASH arg to handler call.

=== modified file 'src/xdisp.c'
--- a/src/xdisp.c       2010-05-27 15:49:01 +0000
+++ b/src/xdisp.c       2010-05-29 10:49:21 +0000
@@ -13763,37 +13763,11 @@
            ++row;
          if (!row->enabled_p)
            rc = CURSOR_MOVEMENT_MUST_SCROLL;
-         /* If rows are bidi-reordered, back up until we find a row
-            that does not belong to a continuation line.  This is
-            because we must consider all rows of a continued line as
-            candidates for cursor positioning, since row start and
-            end positions change non-linearly with vertical position
-            in such rows.  */
-         /* FIXME: Revisit this when glyph ``spilling'' in
-            continuation lines' rows is implemented for
-            bidi-reordered rows.  */
-         if (!NILP (XBUFFER (w->buffer)->bidi_display_reordering))
-           {
-             while (MATRIX_ROW_CONTINUATION_LINE_P (row))
-               {
-                 xassert (row->enabled_p);
-                 --row;
-                 /* If we hit the beginning of the displayed portion
-                    without finding the first row of a continued
-                    line, give up.  */
-                 if (row <= w->current_matrix->rows)
-                   {
-                     rc = CURSOR_MOVEMENT_MUST_SCROLL;
-                     break;
-                   }
-
-               }
-           }
        }
 
       if (rc == CURSOR_MOVEMENT_CANNOT_BE_USED)
        {
-         int scroll_p = 0;
+         int scroll_p = 0, must_scroll = 0;
          int last_y = window_text_bottom_y (w) - this_scroll_margin;
 
          if (PT > XFASTINT (w->last_point))
@@ -13886,10 +13860,41 @@
            {
              /* if PT is not in the glyph row, give up.  */
              rc = CURSOR_MOVEMENT_MUST_SCROLL;
-           }
-         else if (rc != CURSOR_MOVEMENT_SUCCESS
-                  && MATRIX_ROW_PARTIALLY_VISIBLE_P (w, row)
-                  && make_cursor_line_fully_visible_p)
+             must_scroll = 1;
+           }
+         else if (rc != CURSOR_MOVEMENT_SUCCESS
+                  && !NILP (XBUFFER (w->buffer)->bidi_display_reordering))
+           {
+             /* If rows are bidi-reordered and point moved, back up
+                until we find a row that does not belong to a
+                continuation line.  This is because we must consider
+                all rows of a continued line as candidates for the
+                new cursor positioning, since row start and end
+                positions change non-linearly with vertical position
+                in such rows.  */
+             /* FIXME: Revisit this when glyph ``spilling'' in
+                continuation lines' rows is implemented for
+                bidi-reordered rows.  */
+             while (MATRIX_ROW_CONTINUATION_LINE_P (row))
+               {
+                 xassert (row->enabled_p);
+                 --row;
+                 /* If we hit the beginning of the displayed portion
+                    without finding the first row of a continued
+                    line, give up.  */
+                 if (row <= w->current_matrix->rows)
+                   {
+                     rc = CURSOR_MOVEMENT_MUST_SCROLL;
+                     break;
+                   }
+
+               }
+           }
+         if (must_scroll)
+           ;
+         else if (rc != CURSOR_MOVEMENT_SUCCESS
+             && MATRIX_ROW_PARTIALLY_VISIBLE_P (w, row)
+             && make_cursor_line_fully_visible_p)
            {
              if (PT == MATRIX_ROW_END_CHARPOS (row)
                  && !row->ends_at_zv_p
@@ -13915,7 +13920,8 @@
            }
          else if (scroll_p)
            rc = CURSOR_MOVEMENT_MUST_SCROLL;
-         else if (!NILP (XBUFFER (w->buffer)->bidi_display_reordering))
+         else if (rc != CURSOR_MOVEMENT_SUCCESS
+                  && !NILP (XBUFFER (w->buffer)->bidi_display_reordering))
            {
              /* With bidi-reordered rows, there could be more than
                 one candidate row whose start and end positions
@@ -13928,8 +13934,11 @@
 
              do
                {
-                 rv |= set_cursor_from_row (w, row, w->current_matrix,
-                                            0, 0, 0, 0);
+                 if (MATRIX_ROW_START_CHARPOS (row) <= PT
+                     && PT <= MATRIX_ROW_END_CHARPOS (row)
+                     && cursor_row_p (w, row))
+                   rv |= set_cursor_from_row (w, row, w->current_matrix,
+                                              0, 0, 0, 0);
                  /* As soon as we've found the first suitable row
                     whose ends_at_zv_p flag is set, we are done.  */
                  if (rv
@@ -13940,19 +13949,17 @@
                    }
                  ++row;
                }
-             while (MATRIX_ROW_BOTTOM_Y (row) < last_y
-                    && MATRIX_ROW_START_CHARPOS (row) <= PT
-                    && PT <= MATRIX_ROW_END_CHARPOS (row)
-                    && cursor_row_p (w, row));
+             while ((MATRIX_ROW_CONTINUATION_LINE_P (row)
+                     && MATRIX_ROW_BOTTOM_Y (row) <= last_y)
+                    || (MATRIX_ROW_START_CHARPOS (row) == PT
+                        && MATRIX_ROW_BOTTOM_Y (row) < last_y));
              /* If we didn't find any candidate rows, or exited the
                 loop before all the candidates were examined, signal
                 to the caller that this method failed.  */
              if (rc != CURSOR_MOVEMENT_SUCCESS
-                 && (!rv
-                     || (MATRIX_ROW_START_CHARPOS (row) <= PT
-                         && PT <= MATRIX_ROW_END_CHARPOS (row))))
-               rc = CURSOR_MOVEMENT_CANNOT_BE_USED;
-             else
+                 && (!rv || MATRIX_ROW_CONTINUATION_LINE_P (row)))
+               rc = CURSOR_MOVEMENT_MUST_SCROLL;
+             else if (rv)
                rc = CURSOR_MOVEMENT_SUCCESS;
            }
          else