Continue work on continuation lines. Some progress with cursor motion.

 xdisp.c (set_cursor_from_row): Don't overwrite cursor position
 if it is not a better candidate than what we already have.
 (display_line): Keep calling set_cursor_from_row for
 bidi-reordered rows even if we already have a possible candidate
 for cursor position.  Undo the row_end setting throughout the
 code, and instead do it after all the row's glyphs have been
 produced, by looping over the glyphs.

2 files changed, 81 insertions, 24 deletions

diff --git a/src/ChangeLog.bidi b/src/ChangeLog.bidi
index 73fd6bf8da2..22a19c66300 100644
--- a/src/ChangeLog.bidi
+++ b/src/ChangeLog.bidi
@@ -1,3 +1,13 @@
+2010-02-13  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (set_cursor_from_row): Don't overwrite cursor position
+        if it is not a better candidate than what we already have.
+        (display_line): Keep calling set_cursor_from_row for
+        bidi-reordered rows even if we already have a possible candidate
+        for cursor position.  Undo the row_end setting throughout the
+        code, and instead do it after all the row's glyphs have been
+        produced, by looping over the glyphs.
+
 2010-02-06  Eli Zaretskii  <eliz@gnu.org>
 
         Start working on cursor movement in continuation lines.
diff --git a/src/xdisp.c b/src/xdisp.c
index 8f366134cea..e8a77af8935 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -13008,6 +13008,32 @@ set_cursor_from_row (w, row, matrix, delta, delta_bytes, dy, dvpos)
         }
     }
 
+  /* ROW could be part of a continued line, which might have other
+     rows whose start and end charpos occlude point.  Only set
+     w->cursor if we found a better approximation to the cursor
+     position than we have from previously examined rows.  */
+  if (w->cursor.vpos >= 0)
+    {
+      struct glyph *g1 =
+        MATRIX_ROW_GLYPH_START (matrix, w->cursor.vpos) + w->cursor.hpos;
+
+      /* Keep the candidate whose buffer position is the closest to
+         point.  */
+      if (BUFFERP (g1->object)
+          && (g1->charpos == pt_old /* an exact match always wins */
+              || (BUFFERP (glyph->object)
+                  && eabs (g1->charpos - pt_old)
+                   < eabs (glyph->charpos - pt_old))))
+        return 0;
+      /* Keep the candidate that comes from a row spanning less buffer
+         positions.  This may win when one or both candidate positions
+         are on glyphs that came from display strings, for which we
+         cannot compare buffer positions.  */
+      if (MATRIX_ROW_END_CHARPOS (MATRIX_ROW (matrix, w->cursor.vpos))
+          - MATRIX_ROW_START_CHARPOS (MATRIX_ROW (matrix, w->cursor.vpos))
+          < MATRIX_ROW_END_CHARPOS (row) - MATRIX_ROW_START_CHARPOS (row))
+        return 0;
+    }
   w->cursor.hpos = glyph - row->glyphs[TEXT_AREA];
   w->cursor.x = x;
   w->cursor.vpos = MATRIX_ROW_VPOS (row, matrix) + dvpos;
@@ -17160,7 +17186,6 @@ display_line (it)
              even if this row ends in ZV.  */
           if (row->reversed_p)
             extend_face_to_end_of_line (it);
-          row_end = it->current;
           break;
         }
 
@@ -17395,7 +17420,6 @@ display_line (it)
                       it->max_phys_descent = phys_descent;
                     }
 
-                  row_end = it->current;
                   break;
                 }
               else if (new_x > it->first_visible_x)
@@ -17429,10 +17453,7 @@ display_line (it)
 
           /* End of this display line if row is continued.  */
           if (row->continued_p || row->ends_at_zv_p)
-            {
-              row_end = it->current;
-              break;
-            }
+            break;
         }
 
     at_end_of_line:
@@ -17458,22 +17479,8 @@ display_line (it)
             row->glyphs[TEXT_AREA]->charpos = CHARPOS (it->position);
 
           /* Consume the line end.  This skips over invisible lines.  */
-          if (it->bidi_p)
-            {
-              /* When we are reordering bidi text, we still need the
-                 next character in logical order, to set row->end
-                 correctly below.  */
-              push_it (it);
-              it->bidi_p = 0;
-              set_iterator_to_next (it, 1);
-              row_end = it->current;
-              pop_it (it);
-              it->bidi_p = 1;
-            }
           set_iterator_to_next (it, 1);
           it->continuation_lines_width = 0;
-          if (!it->bidi_p)
-            row_end = it->current;
           break;
         }
 
@@ -17511,7 +17518,6 @@ display_line (it)
                   it->continuation_lines_width = 0;
                   row->ends_at_zv_p = 1;
                   row->exact_window_width_line_p = 1;
-                  row_end = it->current;
                   break;
                 }
               if (ITERATOR_AT_END_OF_LINE_P (it))
@@ -17527,7 +17533,6 @@ display_line (it)
           row->ends_at_zv_p = FETCH_BYTE (IT_BYTEPOS (*it) - 1) != '\n';
           it->hpos = hpos_before;
           it->current_x = x_before;
-          row_end = it->current;
           break;
         }
     }
@@ -17588,7 +17593,44 @@ display_line (it)
   compute_line_metrics (it);
 
   /* Remember the position at which this line ends.  */
-  row->end = row_end;
+  if (!it->bidi_p)
+    row->end = row_end = it->current;
+  else
+    {
+      EMACS_INT min_pos = ZV, max_pos = BEGV;
+      struct glyph *g;
+      struct it save_it;
+      struct text_pos tpos;
+
+      /* ROW->start and ROW->end must be the smallest and largest
+         buffer positions in ROW.  But if ROW was bidi-reordered,
+         these two positions can be anywhere in the row, so we must
+         rescan all of the ROW's glyphs to find them.  */
+      for (g = row->glyphs[TEXT_AREA];
+           g < row->glyphs[TEXT_AREA] + row->used[TEXT_AREA];
+           g++)
+        {
+          if (BUFFERP (g->object))
+            {
+              if (g->charpos < min_pos)
+                min_pos = g->charpos;
+              if (g->charpos > max_pos)
+                max_pos = g->charpos;
+            }
+        }
+      row->start.pos.charpos = min_pos;
+      row->start.pos.bytepos = CHAR_TO_BYTE (min_pos);
+      /* For ROW->end, we need the display element that is _after_
+         max_pos, in the logical order.  Note that this may be after
+         skipping some invisible text.  */
+      save_it = *it;
+      it->bidi_p = 0;
+      SET_TEXT_POS (tpos, max_pos, CHAR_TO_BYTE (max_pos));
+      reseat_1 (it, tpos, 0);
+      set_iterator_to_next (it, 1);
+      row->end = row_end = it->current;
+      *it = save_it;
+    }
 
   /* Record whether this row ends inside an ellipsis.  */
   row->ends_in_ellipsis_p
@@ -17607,7 +17649,12 @@ display_line (it)
   it->right_user_fringe_face_id = 0;
 
   /* Maybe set the cursor.  */
-  if (it->w->cursor.vpos < 0
+  if ((it->w->cursor.vpos < 0
+       /* In bidi-reordered rows, keep checking for proper cursor
+          position even if one has been found already, because buffer
+          positions in such rows change non-linearly with ROW->VPOS,
+          when a line is continued.  */
+       || it->bidi_p)
       && PT >= MATRIX_ROW_START_CHARPOS (row)
       && PT <= MATRIX_ROW_END_CHARPOS (row)
       && cursor_row_p (it->w, row))