[Emacs-diffs] emacs-26 671dc5a: Fix calls to buffer modification hooks from replace-buffer-contents

[Eli Zaretskii]

branch: emacs-26
commit 671dc5a51edfb9aaea943e144997e7c1297f56fb
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Fix calls to buffer modification hooks from replace-buffer-contents
    
    * src/editfns.c (Freplace_buffer_contents): Don't call buffer
    modification hooks if nothing was deleted/inserted.  (Bug#32237)
---
 src/editfns.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/editfns.c b/src/editfns.c
index d1a6bfb..cf596ae 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -3254,10 +3254,12 @@ differences between the two buffers.  */)
       from = BEGV + k;
 
       /* Find the last character position to be changed.  */
-      for (l = size_a; l > 0 && !bit_is_set (ctx.deletions, l - 1); l--)
+      for (l = size_a; l > k && !bit_is_set (ctx.deletions, l - 1); l--)
        ;
       to = BEGV + l;
-      prepare_to_modify_buffer (from, to, NULL);
+      /* If k >= l, it means nothing needs to be deleted.  */
+      if (k < l)
+       prepare_to_modify_buffer (from, to, NULL);
       specbind (Qinhibit_modification_hooks, Qt);
       modification_hooks_inhibited = true;
     }
@@ -3308,11 +3310,16 @@ differences between the two buffers.  */)
   SAFE_FREE ();
   rbc_quitcounter = 0;
 
-  if (modification_hooks_inhibited)
+  if (modification_hooks_inhibited && from <= to)
     {
       ptrdiff_t updated_to = to + ZV - BEGV - size_a;
-      signal_after_change (from, to - from, updated_to - from);
-      update_compositions (from, updated_to, CHECK_INSIDE);
+      /* Only call after-change-functions if something was actually
+        inserted.  */
+      if (from < updated_to)
+       {
+         signal_after_change (from, to - from, updated_to - from);
+         update_compositions (from, updated_to, CHECK_INSIDE);
+       }
     }
 
   return Qnil;