Fix bug #11063 with move_it_by_lines when there's a before-string at bol.

[bpt/emacs.git] / src / xdisp.c

diff --git a/src/xdisp.c b/src/xdisp.c
index 302a09d..dcd14a1 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -8966,7 +8966,6 @@ move_it_by_lines (struct it *it, int dvpos)
     {
       /* DVPOS == 0 means move to the start of the screen line.  */
       move_it_vertically_backward (it, 0);
-      xassert (it->current_x == 0 && it->hpos == 0);
       /* Let next call to line_bottom_y calculate real line height */
       last_height = 0;
     }
@@ -8974,7 +8973,20 @@ move_it_by_lines (struct it *it, int dvpos)
     {
       move_it_to (it, -1, -1, -1, it->vpos + dvpos, MOVE_TO_VPOS);
       if (!IT_POS_VALID_AFTER_MOVE_P (it))
-       move_it_to (it, IT_CHARPOS (*it) + 1, -1, -1, -1, MOVE_TO_POS);
+       {
+         /* Only move to the next buffer position if we ended up in a
+            string from display property, not in an overlay string
+            (before-string or after-string).  That is because the
+            latter don't conceal the underlying buffer position, so
+            we can ask to move the iterator to the exact position we
+            are interested in.  Note that, even if we are already at
+            IT_CHARPOS (*it), the call below is not a no-op, as it
+            will detect that we are at the end of the string, pop the
+            iterator, and compute it->current_x and it->hpos
+            correctly.  */
+         move_it_to (it, IT_CHARPOS (*it) + it->string_from_display_prop_p,
+                     -1, -1, -1, MOVE_TO_POS);
+       }
     }
   else
     {