bug#31073: 27.0.50; query-replace undo might change the word case

bug#31073: 27.0.50; query-replace undo might change the word case

[Tino Calancha]

X-Debbugs-CC: Juri Linkov <juri@jurta.org>

The undo feature shouldn't change the case; it must return
to the original words.

emacs -Q
<
M-% t RET FOO RET SPC SPC SPC SPC U
;; The first line shows upcase 'T' at several positions, for instance
;; it shows 'TexT', originally shown as 'text'.


--8<-----------------------------cut here---------------start------------->8---
commit 6fcb746c4efcbc2afce6a520f4a8b67a8d40cdd1
Author: Tino Calancha <tino.calancha@gmail.com>
Date:   Fri Apr 6 13:40:06 2018 +0900

    Preserve case in query-replace undo
    
    If the user query and replaces 'foo' with 'BAR', then
    undo must comeback to 'foo', not to 'FOO'.
    * lisp/replace.el (perform-replace): Bind nocasify to non-nil
    value during undo/undo-all actions.
    * test/lisp/replace-tests.el (query-replace-undo-bug31073): Add test.

diff --git a/lisp/replace.el b/lisp/replace.el
index c28c9b36f0..a147c8dd86 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -2619,6 +2619,7 @@ perform-replace
 			   (let ((stack-idx         0)
                                  (stack-len         (length stack))
                                  (num-replacements  0)
+                                 (nocasify t) ; Bug#31073.
                                  search-string
                                  next-replacement)
                              (while (and (< stack-idx stack-len)
diff --git a/test/lisp/replace-tests.el b/test/lisp/replace-tests.el
index 66c6842660..d6043e297c 100644
--- a/test/lisp/replace-tests.el
+++ b/test/lisp/replace-tests.el
@@ -380,4 +380,24 @@ replace-tests--query-replace-undo
   (should (string= "211" (replace-tests--query-replace-undo)))
   (should (string= "211" (replace-tests--query-replace-undo 'comma))))
 
+(ert-deftest query-replace-undo-bug31073 ()
+  "Test for https://debbugs.gnu.org/31073 ."
+  (let ((text "The teeth must be cleaned after every meal.")
+        (count 0))
+    (with-temp-buffer
+      (insert text)
+      (goto-char 1)
+      (cl-letf (((symbol-function 'read-event)
+                 (lambda (&rest args)
+                   (cl-incf count)
+                   (let ((val (pcase count
+                                ('4 ?U) ; undo-all
+                                ('5 ?q) ; exit
+                                (_ ?\s)))) ; replace current and go next
+                     val))))
+        (perform-replace "t" "FOO" t nil nil))
+      ;; After undo text must be the same.
+      (should (string= text (buffer-string))))))
+
+
 ;;; replace-tests.el ends here
--8<-----------------------------cut here---------------end--------------->8---
In GNU Emacs 27.0.50 (build 25, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2018-04-03 built on calancha-pc
Repository revision: 10ef466a9eb621a3752de69930fcb14bf1af4887

bug#31073: 27.0.50; query-replace undo might change the word case

[Juri Linkov]

> The undo feature shouldn't change the case; it must return
> to the original words.
>
> emacs -Q
> <
> M-% t RET FOO RET SPC SPC SPC SPC U
> ;; The first line shows upcase 'T' at several positions, for instance
> ;; it shows 'TexT', originally shown as 'text'.

Good catch!  This means we should have more test coverage.  Thanks.

bug#31073: 27.0.50; query-replace undo might change the word case

[Tino Calancha]

Juri Linkov <juri@jurta.org> writes:

>> The undo feature shouldn't change the case; it must return
>> to the original words.
>>
>> emacs -Q
>> <
>> M-% t RET FOO RET SPC SPC SPC SPC U
>> ;; The first line shows upcase 'T' at several positions, for instance
>> ;; it shows 'TexT', originally shown as 'text'.
>
> Good catch!  This means we should have more test coverage.  Thanks.
Eli,

this feature was introduced for Emacs-26 release.  Should the fix go
into that branch (Emacs-26)?

bug#31073: 27.0.50; query-replace undo might change the word case

[Eli Zaretskii]

> From: Tino Calancha <tino.calancha@gmail.com>
> Cc: 31073@debbugs.gnu.org, Juri Linkov <juri@jurta.org>
> Date: Sun, 08 Apr 2018 10:14:01 +0900
> 
> Juri Linkov <juri@jurta.org> writes:
> 
> >> The undo feature shouldn't change the case; it must return
> >> to the original words.
> >>
> >> emacs -Q
> >> <
> >> M-% t RET FOO RET SPC SPC SPC SPC U
> >> ;; The first line shows upcase 'T' at several positions, for instance
> >> ;; it shows 'TexT', originally shown as 'text'.
> >
> > Good catch!  This means we should have more test coverage.  Thanks.
> Eli,
> 
> this feature was introduced for Emacs-26 release.  Should the fix go
> into that branch (Emacs-26)?

It's too late for Emacs 26.1.  For the other 26.x, I'd need to see the
patch first.

Thanks.

bug#31073: 27.0.50; query-replace undo might change the word case

[Tino Calancha]

Eli Zaretskii <eliz@gnu.org> writes:

>> this feature was introduced for Emacs-26 release.  Should the fix go
>> into that branch (Emacs-26)?
>
> It's too late for Emacs 26.1.  For the other 26.x, I'd need to see the
> patch first.
I see.
The patch is pretty obvious: just 1 line:

--8<-----------------------------cut here---------------start------------->8---
commit a70414e82048f425cdb00e3cd30c15fcb9fbab86
Author: Tino Calancha <tino.calancha@gmail.com>
Date:   Fri Apr 6 14:03:55 2018 +0900

    Preserve case in query-replace undo
    
    If the user query and replaces 'foo' with 'BAR', then
    undo must comeback to 'foo', not to 'FOO' (Bug#31073).
    * lisp/replace.el (perform-replace): Bind nocasify to non-nil
    value during undo/undo-all actions.

diff --git a/lisp/replace.el b/lisp/replace.el
index c28c9b36f0..2b0555d580 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -2619,6 +2619,7 @@ perform-replace
 			   (let ((stack-idx         0)
                                  (stack-len         (length stack))
                                  (num-replacements  0)
+                                 (nocasify t) ; Bug#31073.
                                  search-string
                                  next-replacement)
                              (while (and (< stack-idx stack-len)

--8<-----------------------------cut here---------------end--------------->8---
In GNU Emacs 27.0.50 (build 25, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
Repository revision: 8df23a82042fa7dbaaa4377bc376d705595b073f

bug#31073: 27.0.50; query-replace undo might change the word case

[Eli Zaretskii]

> From: Tino Calancha <tino.calancha@gmail.com>
> Cc: juri@jurta.org,  31073@debbugs.gnu.org
> Date: Sun, 08 Apr 2018 11:46:15 +0900
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> this feature was introduced for Emacs-26 release.  Should the fix go
> >> into that branch (Emacs-26)?
> >
> > It's too late for Emacs 26.1.  For the other 26.x, I'd need to see the
> > patch first.
> I see.
> The patch is pretty obvious: just 1 line:

Thanks.  This is indeed OK for the emacs-26 branch, but please wait
with pushing this until Emacs 26.1 is released, hopefully soon enough.

Alternatively, feel free to push to master and cherry-pick to emacs-26
later, after the 26.1 release.

bug#31073: 27.0.50; query-replace undo might change the word case

[Tino Calancha]

Eli Zaretskii <eliz@gnu.org> writes:

>> The patch is pretty obvious: just 1 line:
>
> Thanks.  This is indeed OK for the emacs-26 branch, but please wait
> with pushing this until Emacs 26.1 is released, hopefully soon enough.
>
> Alternatively, feel free to push to master and cherry-pick to emacs-26
> later, after the 26.1 release.
Pushed fix into master branch as commit
"Preserve case in query-replace undo"
(32dc0cb1b5ae895d237c7118ccaeb084715934fd).

I will backport the fix to emacs-26 after 26.1 release.