bug#37287: 26.3.50; query-replace-regexp undo does not update next-replacement

[Tino Calancha]

emacs -Q
C-x b foo RET
M-: (insert "foo-1\nfoo-2\nfoo-3") RET
M-<
C-M-% \([0-9]\) RET
\,(format "%d" (1+ (string-to-number \1))) RET
SPC
SPC
U
SPC
q

;; buffer contains
"foo-4\nfoo-2\nfoo-3"
;; expected
"foo-2\nfoo-2\nfoo-3"

--8<-----------------------------cut here---------------start------------->8---
commit ff57cbdde0ae9382e043bf335a52ed91ba1b205e
Author: Tino Calancha <tino.calancha@gmail.com>
Date:   Mon Sep 2 21:58:04 2019 +0200

    query-replace-regexp undo: Update next-replacement after undo
    
    * lisp/replace.el (perform-replace):
    Use last-replacement for the local binding to not shadow next-replacement.
    Update next-replacement after undo (Bug#37287).
    
    * test/lisp/replace-tests.el (query-replace-undo-bug37287): Add test.
    (query-replace-undo-bug37073): Tweak this test.

diff --git a/lisp/replace.el b/lisp/replace.el
index 0ddebb1270..dd24d8ba92 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -2584,7 +2584,7 @@ perform-replace
                                  (num-replacements  0)
                                  (nocasify t) ; Undo must preserve case 
(Bug#31073).
                                  search-string
-                                 next-replacement)
+                                 last-replacement)
                              (while (and (< stack-idx stack-len)
                                          stack
                                          (or (null replaced) 
last-was-act-and-show))
@@ -2595,9 +2595,9 @@ perform-replace
                                   ;; Bind swapped values
                                   ;; (search-string <--> replacement)
                                   search-string (nth (if replaced 4 3) elt)
-                                  next-replacement (nth (if replaced 3 4) elt)
+                                  last-replacement (nth (if replaced 3 4) elt)
                                   search-string-replaced search-string
-                                  next-replacement-replaced next-replacement
+                                  last-replacement-replaced last-replacement
                                   last-was-act-and-show nil)
 
                                  (when (and (= stack-idx stack-len)
@@ -2619,16 +2619,18 @@ perform-replace
                                            (match-data t (nth 2 elt)))
                                          noedit
                                          (replace-match-maybe-edit
-                                          next-replacement nocasify literal
+                                          last-replacement nocasify literal
                                           noedit real-match-data backward)
                                          replace-count (1- replace-count)
                                          real-match-data
                                          (save-excursion
                                            (goto-char (match-beginning 0))
                                            (if regexp-flag
-                                               (looking-at next-replacement)
-                                             (looking-at (regexp-quote 
next-replacement)))
+                                               (looking-at last-replacement)
+                                             (looking-at (regexp-quote 
last-replacement)))
                                            (match-data t (nth 2 elt))))
+                                   (when regexp-flag
+                                     (setq next-replacement (nth 4 elt)))
                                    ;; Set replaced nil to keep in loop
                                    (when (eq def 'undo-all)
                                      (setq replaced nil
diff --git a/test/lisp/replace-tests.el b/test/lisp/replace-tests.el
index cd08a522e3..2a3f207e47 100644
--- a/test/lisp/replace-tests.el
+++ b/test/lisp/replace-tests.el
@@ -463,7 +463,9 @@ replace-tests--query-replace-undo
     (should
      (replace-tests-with-undo
          input "theorem \\([0-9]+\\)"
-         "theorem \\\\ref{theo_\\1}"
+         '(replace-eval-replacement
+           replace-quote
+           (format "theorem \\\\ref{theo_%d}" (1+ (string-to-number 
(match-string 1)))))
          ((?\s . (1 2)) (?U . (3)))
          ?q
        (string= input (buffer-string)))))
@@ -479,4 +481,18 @@ replace-tests--query-replace-undo
          ?q
        (string= expected (buffer-string))))))
 
+(ert-deftest query-replace-undo-bug37287 ()
+  "Test for https://debbugs.gnu.org/37287 ."
+  (let ((input "foo-1\nfoo-2\nfoo-3")
+        (expected "foo-2\nfoo-2\nfoo-3"))
+    (should
+     (replace-tests-with-undo
+      input "\\([0-9]\\)"
+      '(replace-eval-replacement
+        replace-quote
+        (format "%d" (1+ (string-to-number (match-string 1)))))
+      ((?\s . (1 2 4)) (?U . (3)))
+      ?q
+      (string= expected (buffer-string))))))
+
 ;;; replace-tests.el ends here
--8<-----------------------------cut here---------------end--------------->8---

In GNU Emacs 26.3.50 (build 4, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2019-09-02 built on calancha-pc.dy.bbexcite.jp
Repository revision: 7e527af72cae65fdb3f61c7d92907cfdfd1e6ea3
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description:     Debian GNU/Linux 10 (buster)