Adjust how `replace-match' runs modification hooks

* src/editfns.c (Fsubst_char_in_region)
(Ftranslate_region_internal):
* src/cmds.c (internal_self_insert): Update callers.
* src/insdel.c (replace_range): Allow inhibiting
signal_after_change/update_compositions.
* src/lisp.h: Update.

* src/search.c (Freplace_match): Run the modification hooks at the
end instead of before adjusting point (bug#42424).

etc/NEWS

@@ -2920,6 +2920,15 @@ This is to keep the same behavior as Eshell.
 
 * Incompatible Lisp Changes in Emacs 28.1
 
+---
+** 'replace-match' now runs modification hooks slightly later.
+The function is documented to leave point after the replacement text,
+but this was not always the case if a modification hook inserted text
+in front of the replaced text -- 'replace-match' would instead leave
+point where the end of the inserted text would have been before the
+hook ran.  'replace-match' now always leaves point after the
+replacement text.
+
 ---
 ** 'kill-all-local-variables' has changed how it handles non-symbol hooks.
 The function is documented to eliminate all buffer-local bindings

src/cmds.c

@@ -455,7 +455,7 @@ internal_self_insert (int c, EMACS_INT n)
       ptrdiff_t to;
       if (INT_ADD_WRAPV (PT, chars_to_delete, &to))
 	to = PTRDIFF_MAX;
-      replace_range (PT, to, string, 1, 1, 1, 0);
+      replace_range (PT, to, string, 1, 1, 1, 0, false);
       Fforward_char (make_fixnum (n));
     }
   else if (n > 1)

src/editfns.c

@@ -2371,7 +2371,7 @@ Both characters must have the same length of multi-byte form.  */)
 	      /* replace_range is less efficient, because it moves the gap,
 		 but it handles combining correctly.  */
 	      replace_range (pos, pos + 1, string,
-			     false, false, true, false);
+			     false, false, true, false, false);
 	      pos_byte_next = CHAR_TO_BYTE (pos);
 	      if (pos_byte_next > pos_byte)
 		/* Before combining happened.  We should not increment
@@ -2578,7 +2578,7 @@ It returns the number of characters changed.  */)
 		     but it should handle multibyte characters correctly.  */
 		  string = make_multibyte_string ((char *) str, 1, str_len);
 		  replace_range (pos, pos + 1, string,
-				 true, false, true, false);
+				 true, false, true, false, false);
 		  len = str_len;
 		}
 	      else
@@ -2613,7 +2613,8 @@ It returns the number of characters changed.  */)
 		= (VECTORP (val)
 		   ? Fconcat (1, &val)
 		   : Fmake_string (make_fixnum (1), val, Qnil));
-	      replace_range (pos, pos + len, string, true, false, true, false);
+	      replace_range (pos, pos + len, string, true, false, true, false,
+			     false);
 	      pos_byte += SBYTES (string);
 	      pos += SCHARS (string);
 	      characters_changed += SCHARS (string);

src/insdel.c

@@ -1392,7 +1392,7 @@ adjust_after_insert (ptrdiff_t from, ptrdiff_t from_byte,
 void
 replace_range (ptrdiff_t from, ptrdiff_t to, Lisp_Object new,
                bool prepare, bool inherit, bool markers,
-               bool adjust_match_data)
+               bool adjust_match_data, bool inhibit_mod_hooks)
 {
   ptrdiff_t inschars = SCHARS (new);
   ptrdiff_t insbytes = SBYTES (new);
@@ -1552,8 +1552,11 @@ replace_range (ptrdiff_t from, ptrdiff_t to, Lisp_Object new,
   if (adjust_match_data)
     update_search_regs (from, to, from + SCHARS (new));
 
-  signal_after_change (from, nchars_del, GPT - from);
-  update_compositions (from, GPT, CHECK_BORDER);
+  if (!inhibit_mod_hooks)
+    {
+      signal_after_change (from, nchars_del, GPT - from);
+      update_compositions (from, GPT, CHECK_BORDER);
+    }
 }
 
 /* Replace the text from character positions FROM to TO with

src/lisp.h

@@ -3717,7 +3717,8 @@ extern void adjust_markers_for_delete (ptrdiff_t, ptrdiff_t,
 				       ptrdiff_t, ptrdiff_t);
 extern void adjust_markers_bytepos (ptrdiff_t, ptrdiff_t,
 				    ptrdiff_t, ptrdiff_t, int);
-extern void replace_range (ptrdiff_t, ptrdiff_t, Lisp_Object, bool, bool, bool, bool);
+extern void replace_range (ptrdiff_t, ptrdiff_t, Lisp_Object, bool, bool,
+			   bool, bool, bool);
 extern void replace_range_2 (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t,
 			     const char *, ptrdiff_t, ptrdiff_t, bool);
 extern void syms_of_insdel (void);

src/search.c

@@ -30,6 +30,7 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include "blockinput.h"
 #include "intervals.h"
 #include "pdumper.h"
+#include "composite.h"
 
 #include "regex-emacs.h"
 
@@ -2725,7 +2726,7 @@ since only regular expressions have distinguished subexpressions.  */)
   newpoint = sub_start + SCHARS (newtext);
 
   /* Replace the old text with the new in the cleanest possible way.  */
-  replace_range (sub_start, sub_end, newtext, 1, 0, 1, true);
+  replace_range (sub_start, sub_end, newtext, 1, 0, 1, true, true);
 
   if (case_action == all_caps)
     Fupcase_region (make_fixnum (search_regs.start[sub]),
@@ -2750,6 +2751,9 @@ since only regular expressions have distinguished subexpressions.  */)
   /* Now move point "officially" to the end of the inserted replacement.  */
   move_if_not_intangible (newpoint);
 
+  signal_after_change (sub_start, sub_end - sub_start, SCHARS (newtext));
+  update_compositions (sub_start, newpoint, CHECK_BORDER);
+
   return Qnil;
 }
 

test/src/search-tests.el

@@ -0,0 +1,42 @@
+;;; search-tests.el --- tests for search.c functions -*- lexical-binding: t -*-
+
+;; Copyright (C) 2015-2016, 2018-2021 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+
+(ert-deftest test-replace-match-modification-hooks ()
+  (let ((ov-set nil))
+    (with-temp-buffer
+      (insert "1 abc")
+      (setq ov-set (make-overlay 3 5))
+      (overlay-put
+       ov-set 'modification-hooks
+       (list (lambda (o after &rest _args)
+	       (when after
+		 (let ((inhibit-modification-hooks t))
+		   (save-excursion
+		     (goto-char 2)
+		     (insert "234")))))))
+      (goto-char 3)
+      (if (search-forward "bc")
+	  (replace-match "bcd"))
+      (should (= (point) 10)))))
+
+;;; search-tests.el ends here