Fix bug #14476 with posn-at-point and glyphs from display vector.

 src/xdisp.c (pos_visible_p): When CHARPOS is displayed frrom a
 display vector, and we backtrack, handle the case that the
 previous character position is also displayed from a display
 vector or covered by a display string or image.

2 files changed, 37 insertions, 7 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 5bcdb7ed068..b1f13e62b40 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2013-05-27  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (pos_visible_p): When CHARPOS is displayed frrom a
+        display vector, and we backtrack, handle the case that the
+        previous character position is also displayed from a display
+        vector or covered by a display string or image.  (Bug#14476)
+
 2013-05-25  Jan Djärv  <jan.h.d@swipnet.se>
 
         * xfns.c (Qgeometry, Qworkarea, Qmm_size, Qframes, Qsource): Remove.
diff --git a/src/xdisp.c b/src/xdisp.c
index 5e92f3643c0..9f3be44ecfd 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1371,18 +1371,41 @@ pos_visible_p (struct window *w, ptrdiff_t charpos, int *x, int *y,
                 top_x = it.glyph_row->x;
               else
                 {
-                  struct it it2;
+                  struct it it2, it2_prev;
+                  /* The idea is to get to the previous buffer
+                     position, consume the character there, and use
+                     the pixel coordinates we get after that.  But if
+                     the previous buffer position is also displayed
+                     from a display vector, we need to consume all of
+                     the glyphs from that display vector.  */
                   start_display (&it2, w, top);
                   move_it_to (&it2, charpos - 1, -1, -1, -1, MOVE_TO_POS);
-                  get_next_display_element (&it2);
-                  PRODUCE_GLYPHS (&it2);
-                  if (ITERATOR_AT_END_OF_LINE_P (&it2)
-                      || it2.current_x > it2.last_visible_x)
+                  /* If we didn't get to CHARPOS - 1, there's some
+                     replacing display property at that position, and
+                     we stopped after it.  That is exactly the place
+                     whose coordinates we want.  */
+                  if (IT_CHARPOS (it2) != charpos - 1)
+                    it2_prev = it2;
+                  else
+                    {
+                      /* Iterate until we get out of the display
+                         vector that displays the character at
+                         CHARPOS - 1.  */
+                      do {
+                        get_next_display_element (&it2);
+                        PRODUCE_GLYPHS (&it2);
+                        it2_prev = it2;
+                        set_iterator_to_next (&it2, 1);
+                      } while (it2.method == GET_FROM_DISPLAY_VECTOR
+                               && IT_CHARPOS (it2) < charpos);
+                    }
+                  if (ITERATOR_AT_END_OF_LINE_P (&it2_prev)
+                      || it2_prev.current_x > it2_prev.last_visible_x)
                     top_x = it.glyph_row->x;
                   else
                     {
-                      top_x = it2.current_x;
-                      top_y = it2.current_y;
+                      top_x = it2_prev.current_x;
+                      top_y = it2_prev.current_y;
                     }
                 }
             }