(verify_overlay_modification):

Copy TAIL before a hook, in case the hook recenters the overlay lists.

1 files changed, 31 insertions, 6 deletions

diff --git a/src/buffer.c b/src/buffer.c
index b76a024cd32..ed8c3518644 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2044,19 +2044,32 @@ verify_overlay_modification (start, end)
       if (XFASTINT (end) == startpos && insertion)
         {
           prop = Foverlay_get (overlay, Qinsert_in_front_hooks);
-          call_overlay_mod_hooks (prop, overlay, start, end);
+          if (!NILP (prop))
+            {
+              /* Copy TAIL in case the hook recenters the overlay lists.  */
+              tail = Fcopy_sequence (tail);
+              call_overlay_mod_hooks (prop, overlay, start, end);
+            }
         }
       if (XFASTINT (start) == endpos && insertion)
         {
           prop = Foverlay_get (overlay, Qinsert_behind_hooks);
-          call_overlay_mod_hooks (prop, overlay, start, end);
+          if (!NILP (prop))
+            {
+              tail = Fcopy_sequence (tail);
+              call_overlay_mod_hooks (prop, overlay, start, end);
+            }
         }
       if (insertion
           ? (XFASTINT (start) > startpos && XFASTINT (end) < endpos)
           : (XFASTINT (start) >= startpos && XFASTINT (end) <= endpos))
         {
           prop = Foverlay_get (overlay, Qmodification_hooks);
-          call_overlay_mod_hooks (prop, overlay, start, end);
+          if (!NILP (prop))
+            {
+              tail = Fcopy_sequence (tail);
+              call_overlay_mod_hooks (prop, overlay, start, end);
+            }
         }
     }
 
@@ -2078,19 +2091,31 @@ verify_overlay_modification (start, end)
       if (XFASTINT (end) == startpos && insertion)
         {
           prop = Foverlay_get (overlay, Qinsert_in_front_hooks);
-          call_overlay_mod_hooks (prop, overlay, start, end);
+          if (!NILP (prop))
+            {
+              tail = Fcopy_sequence (tail);
+              call_overlay_mod_hooks (prop, overlay, start, end);
+            }
         }
       if (XFASTINT (start) == endpos && insertion)
         {
           prop = Foverlay_get (overlay, Qinsert_behind_hooks);
-          call_overlay_mod_hooks (prop, overlay, start, end);
+          if (!NILP (prop))
+            {
+              tail = Fcopy_sequence (tail);
+              call_overlay_mod_hooks (prop, overlay, start, end);
+            }
         }
       if (insertion
           ? (XFASTINT (start) > startpos && XFASTINT (end) < endpos)
           : (XFASTINT (start) >= startpos && XFASTINT (end) <= endpos))
         {
           prop = Foverlay_get (overlay, Qmodification_hooks);
-          call_overlay_mod_hooks (prop, overlay, start, end);
+          if (!NILP (prop))
+            {
+              tail = Fcopy_sequence (tail);
+              call_overlay_mod_hooks (prop, overlay, start, end);
+            }
         }
     }
 }