Do not avoid creating empty evaporating overlays (Bug#9642).

* buffer.c (Fmove_overlay): Revert the change of 2012-04-23.
That is, do not delete an evaporating overlay if it becomes
empty after its bounds are adjusted to fit within its buffer.
This fix caused other problems, and I'm reverting it until we get
to the bottom of them.

diff --git a/src/ChangeLog b/src/ChangeLog
index 56dd75c0084f401fd1c02c167495dada9a439751..5129c8a0047c819bb03737675dc54a352041b48f 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,12 @@
+2012-04-28  Paul Eggert  <eggert@cs.ucla.edu>
+
+       Do not avoid creating empty evaporating overlays (Bug#9642).
+       * buffer.c (Fmove_overlay): Revert the change of 2012-04-23.
+       That is, do not delete an evaporating overlay if it becomes
+       empty after its bounds are adjusted to fit within its buffer.
+       This fix caused other problems, and I'm reverting it until we get
+       to the bottom of them.
+
 2012-04-27  Chong Yidong  <cyd@gnu.org>
 
        * xselect.c (x_convert_selection): Initialize a pointer (Bug#11315).

diff --git a/src/buffer.c b/src/buffer.c
index 6c2e21c81256ce18bb369b721abf49fb3df47cb6..9bac3ec742b53f8af44eb44ae0729480d684e396 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3682,7 +3682,6 @@ buffer.  */)
   struct buffer *b, *ob;
   Lisp_Object obuffer;
   int count = SPECPDL_INDEX ();
-  ptrdiff_t n_beg, n_end;
 
   CHECK_OVERLAY (overlay);
   if (NILP (buffer))
@@ -3701,23 +3700,15 @@ buffer.  */)
   CHECK_NUMBER_COERCE_MARKER (beg);
   CHECK_NUMBER_COERCE_MARKER (end);
 
+  if (XINT (beg) == XINT (end) && ! NILP (Foverlay_get (overlay, Qevaporate)))
+    return Fdelete_overlay (overlay);
+
   if (XINT (beg) > XINT (end))
     {
       Lisp_Object temp;
       temp = beg; beg = end; end = temp;
     }
 
-  /* First set the overlay boundaries, which may clip them.  */
-  Fset_marker (OVERLAY_START (overlay), beg, buffer);
-  Fset_marker (OVERLAY_END (overlay), end, buffer);
-  n_beg = marker_position (OVERLAY_START (overlay));
-  n_end = marker_position (OVERLAY_END (overlay));
-
-  /* Now, delete the overlay if it is empty after clipping and has the
-     evaporate property.  */
-  if (n_beg == n_end && ! NILP (Foverlay_get (overlay, Qevaporate)))
-    return Fdelete_overlay (overlay);
-
   specbind (Qinhibit_quit, Qt);
 
   obuffer = Fmarker_buffer (OVERLAY_START (overlay));
@@ -3740,7 +3731,7 @@ buffer.  */)
        }
 
       /* Redisplay where the overlay is going to be.  */
-      modify_overlay (b, n_beg, n_end);
+      modify_overlay (b, XINT (beg), XINT (end));
     }
   else
     /* Redisplay the area the overlay has just left, or just enclosed.  */
@@ -3750,12 +3741,16 @@ buffer.  */)
       o_beg = OVERLAY_POSITION (OVERLAY_START (overlay));
       o_end = OVERLAY_POSITION (OVERLAY_END (overlay));
 
-      if (o_beg == n_beg)
-       modify_overlay (b, o_end, n_end);
-      else if (o_end == n_end)
-       modify_overlay (b, o_beg, n_beg);
+      if (o_beg == XINT (beg))
+       modify_overlay (b, o_end, XINT (end));
+      else if (o_end == XINT (end))
+       modify_overlay (b, o_beg, XINT (beg));
       else
-       modify_overlay (b, min (o_beg, n_beg), max (o_end, n_end));
+       {
+         if (XINT (beg) < o_beg) o_beg = XINT (beg);
+         if (XINT (end) > o_end) o_end = XINT (end);
+         modify_overlay (b, o_beg, o_end);
+       }
     }
 
   if (!NILP (obuffer))
@@ -3767,8 +3762,12 @@ buffer.  */)
       eassert (XOVERLAY (overlay)->next == NULL);
     }
 
+  Fset_marker (OVERLAY_START (overlay), beg, buffer);
+  Fset_marker (OVERLAY_END   (overlay), end, buffer);
+
   /* Put the overlay on the wrong list.  */
-  if (n_end < b->overlay_center)
+  end = OVERLAY_END (overlay);
+  if (OVERLAY_POSITION (end) < b->overlay_center)
     {
       XOVERLAY (overlay)->next = b->overlays_after;
       b->overlays_after = XOVERLAY (overlay);