GNU bug report logs - #48695
python.el *-backspace functionality behavior

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Mikhail P <mikpom <at> fastmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: python.el *-backspace functionality behavior
Date: Thu, 27 May 2021 14:11:48 +0700

[Message part 1 (text/plain, inline)]

Hello!

I want to report a small behavior problem of the default python.el

When hitting backspace in some context it does not delete the region 
selected (between active mark and cursor) but dedents instead.

Attaching a video and debug info below.

Thanks, Mikhail


|In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.22, 
cairo version 1.17.3)||
|| of 2020-08-29 built on juergen||
||Windowing system distributor 'The X.Org Foundation', version 
11.0.12010000||
||System Description: Arch Linux||
||
||Recent messages:||
||Please type q, s, or p; or ? for help||
||...ome/mikpom/tmp/test.py locked by mikpom <at> mik-PC... (pid 306092): (s, 
q, p, ?)?  [2 times]||
||point=32 of 31 (EOB) column=11||
||Quit [2 times]||
||point=32 of 31 (EOB) column=11||
||Use +,-,0 for further adjustment [7 times]||
||Mark set||
||Undo||
||Mark set||
||Undo||
||
||Configured using:||
|| 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib||
|| --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-wide-int||
|| --with-modules --with-cairo --with-harfbuzz 'CFLAGS=-march=x86-64||
|| -mtune=generic -O2 -pipe -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2||
|| LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'||
||
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||Important settings:||
||  value of $LANG: en_US.UTF-8||
||  locale-coding-system: utf-8-unix||
||
||Major mode: Python||
||
||Minor modes in effect:||
||  text-scale-mode: t||
||  shell-dirtrack-mode: t||
||  tooltip-mode: t||
||  global-eldoc-mode: t||
||  eldoc-mode: t||
||  electric-indent-mode: t||
||  mouse-wheel-mode: t||
||  tool-bar-mode: t||
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|

[Message part 2 (text/html, inline)]

[2021-05-27 14-06-50.flv (video/x-flv, attachment)]

Message #8 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Mikhail P <mikpom <at> fastmail.com>
Cc: 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: python.el *-backspace functionality behavior
Date: Fri, 28 May 2021 01:32:52 +0200

Mikhail P <mikpom <at> fastmail.com> writes:

> I want to report a small behavior problem of the default python.el 
>
> When hitting backspace in some context it does not delete the region selected
> (between active mark and cursor) but dedents instead.
>
> Attaching a video and debug info below.

I'm unable to reproduce the problem on either Emacs 27.1 or Emacs 28.
Could you give a step-by-step recipe to reproduce the bug, starting from
"emacs -Q"?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #13 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Mikhail P <mikpom <at> fastmail.com>
Cc: 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: python.el *-backspace functionality behavior
Date: Fri, 28 May 2021 03:13:21 +0200

(Please keep the debbugs address in the Cc headers -- otherwise your
mails won't reach the Emacs bug tracker.)

Mikhail P <mikpom <at> fastmail.com> writes:

> Greetings!
>
> The steps are :
>
> 1. start emacs with emacs -Q
>
> 2. visit a (empty) file with .py extension (so built-in Python major mode is activated)
>
> 3. type a block of code containing indented line, e.g. 
>
> for i in range(10): 
>
>     print(i)
>
> 4. Move the cursor at the very end of the code example (after print(i)) and activate
> the mark
>
> 5. Move the cursor at the beginning of print(i), so it is on p.
>
> 6. hit backspace.
>
> 7. selected text (print(i)) is not deleted but dedented instead)

Thanks for the recipe -- I can reproduce this in both Emacs 28 and 27.1.

If point is anywhere else than at the "p", the <backspace> works as
expected, but if it's a the "p", it deletes the leading spaces instead.
Most peculiar.

Message #18 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
To: larsi <at> gnus.org
Cc: mikpom <at> fastmail.com,
 Jakub Ječmínek <kuba <at> kubajecminek.cz>,
 48695 <at> debbugs.gnu.org
Subject: [PATCH] Fix region deletion behavior in python.el
Date: Mon, 30 Jun 2025 00:19:53 +0200

* lisp/progmodes/python.el (python-indent-dedent-line-backspace):
Check for an active region when deciding whether to perform a
backward delete.  (Bug#48695)

* test/lisp/progmodes/python-tests.el: Add regression test
`python-indent-dedent-line-backspace-4'.
---
 lisp/progmodes/python.el            |  4 +++-
 test/lisp/progmodes/python-tests.el | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index f4f0518dbfd..17fabc322fa 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1970,7 +1970,9 @@ python-indent-dedent-line-backspace
 Argument ARG is passed to `backward-delete-char-untabify' when
 point is not in between the indentation."
   (interactive "*p")
-  (unless (python-indent-dedent-line)
+  (unless (and
+           (not (region-active-p))
+           (python-indent-dedent-line))
     (backward-delete-char-untabify arg)))
 
 (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)
diff --git a/test/lisp/progmodes/python-tests.el b/test/lisp/progmodes/python-tests.el
index 2c00f47d82c..f13175c9836 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -3780,6 +3780,21 @@ python-indent-dedent-line-backspace-3
                 (pos-bol) (pos-eol))
                "abcdef")))))
 
+(ert-deftest python-indent-dedent-line-backspace-4 ()
+  "Correctly delete region instead of de-indentation.  Bug#48695."
+  (python-tests-with-temp-buffer
+   "
+if True:
+    x ()
+    if False:
+"
+   (python-tests-look-at "if False:")
+   (end-of-line)
+   (set-mark-command nil)
+   (backward-word 2)
+   (call-interactively #'python-indent-dedent-line-backspace)
+   (should (= (current-indentation) 4))))
+
 (ert-deftest python-bob-infloop-avoid ()
   "Test that strings at BOB don't confuse syntax analysis.  Bug#24905"
   (python-tests-with-temp-buffer
-- 
2.49.0

Message #21 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Jakub Ječmínek <kuba <at> kubajecminek.cz>, kobarity
 <kobarity <at> gmail.com>
Cc: mikpom <at> fastmail.com, kuba <at> kubajecminek.cz, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Mon, 30 Jun 2025 15:27:24 +0300

> Cc: mikpom <at> fastmail.com,
>  Jakub Ječmínek <kuba <at> kubajecminek.cz>,
>  48695 <at> debbugs.gnu.org
> Date: Mon, 30 Jun 2025 00:19:53 +0200
> From:  Jakub Ječmínek via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs <at> gnu.org>
> 
> * lisp/progmodes/python.el (python-indent-dedent-line-backspace):
> Check for an active region when deciding whether to perform a
> backward delete.  (Bug#48695)
> 
> * test/lisp/progmodes/python-tests.el: Add regression test
> `python-indent-dedent-line-backspace-4'.
> ---
>  lisp/progmodes/python.el            |  4 +++-
>  test/lisp/progmodes/python-tests.el | 15 +++++++++++++++
>  2 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
> index f4f0518dbfd..17fabc322fa 100644
> --- a/lisp/progmodes/python.el
> +++ b/lisp/progmodes/python.el
> @@ -1970,7 +1970,9 @@ python-indent-dedent-line-backspace
>  Argument ARG is passed to `backward-delete-char-untabify' when
>  point is not in between the indentation."
>    (interactive "*p")
> -  (unless (python-indent-dedent-line)
> +  (unless (and
> +           (not (region-active-p))
> +           (python-indent-dedent-line))
>      (backward-delete-char-untabify arg)))
>  
>  (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)

This is an incompatible change in behavior.  I wonder whether we can
do this unconditionally.  Maybe some user option is in order to
control this behavior?

kobarity, any comments or suggestions?

Message #24 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: kobarity <kobarity <at> gmail.com>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: mikpom <at> fastmail.com,
 Jakub Ječmínek <kuba <at> kubajecminek.cz>, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Tue, 01 Jul 2025 12:31:24 +0900

Eli Zaretskii wrote:
> > Cc: mikpom <at> fastmail.com,
> >  Jakub Ječmínek <kuba <at> kubajecminek.cz>,
> >  48695 <at> debbugs.gnu.org
> > Date: Mon, 30 Jun 2025 00:19:53 +0200
> > From:  Jakub Ječmínek via "Bug reports for GNU Emacs,
> >  the Swiss army knife of text editors" <bug-gnu-emacs <at> gnu.org>
> > 
> > * lisp/progmodes/python.el (python-indent-dedent-line-backspace):
> > Check for an active region when deciding whether to perform a
> > backward delete.  (Bug#48695)
> > 
> > * test/lisp/progmodes/python-tests.el: Add regression test
> > `python-indent-dedent-line-backspace-4'.
> > ---
> >  lisp/progmodes/python.el            |  4 +++-
> >  test/lisp/progmodes/python-tests.el | 15 +++++++++++++++
> >  2 files changed, 18 insertions(+), 1 deletion(-)
> > 
> > diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
> > index f4f0518dbfd..17fabc322fa 100644
> > --- a/lisp/progmodes/python.el
> > +++ b/lisp/progmodes/python.el
> > @@ -1970,7 +1970,9 @@ python-indent-dedent-line-backspace
> >  Argument ARG is passed to `backward-delete-char-untabify' when
> >  point is not in between the indentation."
> >    (interactive "*p")
> > -  (unless (python-indent-dedent-line)
> > +  (unless (and
> > +           (not (region-active-p))
> > +           (python-indent-dedent-line))
> >      (backward-delete-char-untabify arg)))
> >  
> >  (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)
> 
> This is an incompatible change in behavior.  I wonder whether we can
> do this unconditionally.  Maybe some user option is in order to
> control this behavior?
> 
> kobarity, any comments or suggestions?

How about using `delete-active-region'?  This affects the behavior of
`backward-delete-char-untabify'.  I have a feeling that most people
who set this to nil would prefer the current behavior.

`backward-delete-char-untabify' has the following code.

  (if (and (use-region-p)
           delete-active-region
           (= arg 1))
      ;; Delete the text of the region and deactivate the mark, in the
      ;; same way that `delete-backward-char' does.
      (with-no-warnings (delete-backward-char 1 killp))

I think it would be more consistent to use the same logic as this.

Message #27 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
To: kobarity <kobarity <at> gmail.com>, Eli Zaretskii <eliz <at> gnu.org>
Cc: mikpom <at> fastmail.com, larsi <at> gnus.org, 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Wed, 9 Jul 2025 00:00:49 +0200

On 7/1/25 05:31, kobarity wrote:
> How about using `delete-active-region'?  This affects the behavior of
> `backward-delete-char-untabify'.  I have a feeling that most people
> who set this to nil would prefer the current behavior.
> 
> `backward-delete-char-untabify' has the following code.
> 
>    (if (and (use-region-p)
>             delete-active-region
>             (= arg 1))
>        ;; Delete the text of the region and deactivate the mark, in the
>        ;; same way that `delete-backward-char' does.
>        (with-no-warnings (delete-backward-char 1 killp))
> 
> I think it would be more consistent to use the same logic as this.

Do you mean something like this?

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index f4f0518dbfd..92c0889da8f 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1970,7 +1970,9 @@ python-indent-dedent-line-backspace
 Argument ARG is passed to `backward-delete-char-untabify' when
 point is not in between the indentation."
   (interactive "*p")
-  (unless (python-indent-dedent-line)
+  (when (or
+         (and (use-region-p) delete-active-region)
+         (not (python-indent-dedent-line)))
     (backward-delete-char-untabify arg)))

 (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)

Message #30 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: kobarity <kobarity <at> gmail.com>
To: Jakub Ječmínek <kuba <at> kubajecminek.cz>
Cc: mikpom <at> fastmail.com, Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Wed, 09 Jul 2025 23:26:55 +0900

Jakub Ječmínek wrote:
> 
> On 7/1/25 05:31, kobarity wrote:
> > How about using `delete-active-region'?  This affects the behavior of
> > `backward-delete-char-untabify'.  I have a feeling that most people
> > who set this to nil would prefer the current behavior.
> > 
> > `backward-delete-char-untabify' has the following code.
> > 
> >    (if (and (use-region-p)
> >             delete-active-region
> >             (= arg 1))
> >        ;; Delete the text of the region and deactivate the mark, in the
> >        ;; same way that `delete-backward-char' does.
> >        (with-no-warnings (delete-backward-char 1 killp))
> > 
> > I think it would be more consistent to use the same logic as this.
> 
> Do you mean something like this?
> 
> diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
> index f4f0518dbfd..92c0889da8f 100644
> --- a/lisp/progmodes/python.el
> +++ b/lisp/progmodes/python.el
> @@ -1970,7 +1970,9 @@ python-indent-dedent-line-backspace
>  Argument ARG is passed to `backward-delete-char-untabify' when
>  point is not in between the indentation."
>    (interactive "*p")
> -  (unless (python-indent-dedent-line)
> +  (when (or
> +         (and (use-region-p) delete-active-region)
> +         (not (python-indent-dedent-line)))
>      (backward-delete-char-untabify arg)))
> 
>  (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)

Mostly yes.  I would prefer to add the check for arg being 1 as well.
Doing so has the following advantages:

- Less difference from current behavior.
- The behavior can be controlled by the prefix argument.  (When
  `delete-active-region' is non-nil and the region is not empty.)
- More consistent with `backward-delete-char-untabify'.

In any case, it would be better to update the docstring.

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index f4f0518dbfd..867e945fabb 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1970,7 +1970,9 @@ python-indent-dedent-line-backspace
 Argument ARG is passed to `backward-delete-char-untabify' when
 point is not in between the indentation."
   (interactive "*p")
-  (unless (python-indent-dedent-line)
+  (when (or
+         (and (use-region-p) delete-active-region (= arg 1))
+         (not (python-indent-dedent-line)))
     (backward-delete-char-untabify arg)))
 
 (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)

Message #33 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
To: kobarity <kobarity <at> gmail.com>
Cc: mikpom <at> fastmail.com, Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Wed, 9 Jul 2025 21:35:50 +0200

On 7/9/25 16:26, kobarity wrote:
> Mostly yes.  I would prefer to add the check for arg being 1 as well.

Thank you — adding a check for `(= arg 1)' makes sense here.

> In any case, it would be better to update the docstring.

Agreed. I’ll send a new patch that includes updated docstrings, ERTs, 
and a NEWS entry. However, before doing that, I’d like to hear Eli’s 
opinion: Is using `delete-active-region' appropriate here, or would it 
be better to introduce a new option specific to `python-mode'?

Message #36 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Jakub Ječmínek <kuba <at> kubajecminek.cz>
Cc: mikpom <at> fastmail.com, kobarity <at> gmail.com, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Thu, 10 Jul 2025 09:05:02 +0300

> Date: Wed, 9 Jul 2025 21:35:50 +0200
> Cc: Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org, mikpom <at> fastmail.com,
>  48695 <at> debbugs.gnu.org
> From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
> 
> On 7/9/25 16:26, kobarity wrote:
> > Mostly yes.  I would prefer to add the check for arg being 1 as well.
> 
> Thank you — adding a check for `(= arg 1)' makes sense here.
> 
> > In any case, it would be better to update the docstring.
> 
> Agreed. I’ll send a new patch that includes updated docstrings, ERTs, 
> and a NEWS entry. However, before doing that, I’d like to hear Eli’s 
> opinion: Is using `delete-active-region' appropriate here, or would it 
> be better to introduce a new option specific to `python-mode'?

I think the test for ARG = 1 is enough.

Message #39 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: kuba <at> kubajecminek.cz
Cc: mikpom <at> fastmail.com, kobarity <at> gmail.com, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Sat, 26 Jul 2025 11:18:43 +0300

Ping! Jakub, did you have an opportunity to work on the updated patch?

> Cc: mikpom <at> fastmail.com, kobarity <at> gmail.com, larsi <at> gnus.org,
>  48695 <at> debbugs.gnu.org
> Date: Thu, 10 Jul 2025 09:05:02 +0300
> From: Eli Zaretskii <eliz <at> gnu.org>
> 
> > Date: Wed, 9 Jul 2025 21:35:50 +0200
> > Cc: Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org, mikpom <at> fastmail.com,
> >  48695 <at> debbugs.gnu.org
> > From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
> > 
> > On 7/9/25 16:26, kobarity wrote:
> > > Mostly yes.  I would prefer to add the check for arg being 1 as well.
> > 
> > Thank you — adding a check for `(= arg 1)' makes sense here.
> > 
> > > In any case, it would be better to update the docstring.
> > 
> > Agreed. I’ll send a new patch that includes updated docstrings, ERTs, 
> > and a NEWS entry. However, before doing that, I’d like to hear Eli’s 
> > opinion: Is using `delete-active-region' appropriate here, or would it 
> > be better to introduce a new option specific to `python-mode'?
> 
> I think the test for ARG = 1 is enough.
> 
> 
> 
> 

Message #42 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: mikpom <at> fastmail.com, kobarity <at> gmail.com, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Sat, 26 Jul 2025 21:57:38 +0200

Eli Zaretskii <eliz <at> gnu.org> writes:

> Ping! Jakub, did you have an opportunity to work on the updated patch?

Sorry for the delayed response.  Please see the patch below.

From d10520e9ab362b3667bf06a798316e8afe6e8e64 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Je=C4=8Dm=C3=ADnek?= <kuba <at> kubajecminek.cz>
Date: Sun, 29 Jun 2025 23:56:13 +0200
Subject: [PATCH] Improve region deletion handling in python.el

* lisp/progmodes/python.el (python-indent-dedent-line-backspace):
Delete the text in the region if Transient Mark mode is enabled, the
mark is active, and prefix arg is 1.  (Bug#48695)

* test/lisp/progmodes/python-tests.el: Add new test
`python-indent-dedent-line-backspace-4'.
---
 etc/NEWS                            |  7 +++++++
 lisp/progmodes/python.el            |  9 ++++++---
 test/lisp/progmodes/python-tests.el | 17 +++++++++++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 8d41efdaf64..1ee573213aa 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1809,6 +1809,13 @@ restart Emacs.
 ---
 *** Support of 'electric-layout-mode' added.
 
+---
+*** DEL now deletes the text in the active region when point is between indentation.
+The command 'python-indent-dedent-line-backspace' (by default bound to
+'DEL') now deletes the text in the region and deactivates the mark if
+Transient Mark mode is enabled, the mark is active, and prefix argument
+is 1.
+
 ** Tmm Menubar
 
 ---
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index f4f0518dbfd..8b5ffae57d6 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1967,10 +1967,13 @@ python-indent-dedent-line
 
 (defun python-indent-dedent-line-backspace (arg)
   "De-indent current line.
-Argument ARG is passed to `backward-delete-char-untabify' when
-point is not in between the indentation."
+Argument ARG is passed to `backward-delete-char-untabify' when point is
+not in between the indentation or when Transient Mark mode is enabled,
+the mark is active, and ARG is 1."
   (interactive "*p")
-  (unless (python-indent-dedent-line)
+  (when (or
+         (and (use-region-p) (= arg 1))
+         (not (python-indent-dedent-line)))
     (backward-delete-char-untabify arg)))
 
 (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)
diff --git a/test/lisp/progmodes/python-tests.el b/test/lisp/progmodes/python-tests.el
index 2c00f47d82c..d9aad7c7034 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -3780,6 +3780,23 @@ python-indent-dedent-line-backspace-3
                 (pos-bol) (pos-eol))
                "abcdef")))))
 
+(ert-deftest python-indent-dedent-line-backspace-4 ()
+  "Delete the text in the region instead of de-indentation.  Bug#48695."
+  (dolist (test '((1 4) (2 0)))
+    (python-tests-with-temp-buffer
+        "
+if True:
+    x ()
+    if False:
+"
+      (let ((current-prefix-arg (list (car test))))
+        (python-tests-look-at "if False:")
+        (end-of-line)
+        (set-mark-command nil)
+        (backward-word 2)
+        (call-interactively #'python-indent-dedent-line-backspace)
+        (should (= (current-indentation) (cadr test)))))))
+
 (ert-deftest python-bob-infloop-avoid ()
   "Test that strings at BOB don't confuse syntax analysis.  Bug#24905"
   (python-tests-with-temp-buffer
-- 
2.49.1

Message #45 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: kobarity <kobarity <at> gmail.com>
To: Jakub Ječmínek <kuba <at> kubajecminek.cz>
Cc: mikpom <at> fastmail.com, Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Sun, 27 Jul 2025 23:48:35 +0900

Jakub Ječmínek wrote:
> 
> Eli Zaretskii <eliz <at> gnu.org> writes:
> 
> > Ping! Jakub, did you have an opportunity to work on the updated patch?
> 
> Sorry for the delayed response.  Please see the patch below.

`python-indent-dedent-line-backspace-4' seems to fail in batch mode.
It would be better to use

        (transient-mark-mode)
        (set-mark (point))

instead of

        (set-mark-command nil)

Message #48 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: Jakub Ječmínek <kuba <at> kubajecminek.cz>
To: kobarity <kobarity <at> gmail.com>
Cc: mikpom <at> fastmail.com, Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Sun, 27 Jul 2025 22:57:46 +0200

kobarity <kobarity <at> gmail.com> writes:

> `python-indent-dedent-line-backspace-4' seems to fail in batch mode.
> It would be better to use
>
>         (transient-mark-mode)
>         (set-mark (point))
>
> instead of
>
>         (set-mark-command nil)

Oops, here's revised version. Thanks!

From 405e06443a2d75ddb3e5b8c245dd65bbb5c2d25a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Je=C4=8Dm=C3=ADnek?= <kuba <at> kubajecminek.cz>
Date: Sun, 29 Jun 2025 23:56:13 +0200
Subject: [PATCH] Improve region deletion handling in python.el

* lisp/progmodes/python.el (python-indent-dedent-line-backspace):
Delete the text in the region if Transient Mark mode is enabled, the
mark is active, and prefix arg is 1.  (Bug#48695)

* test/lisp/progmodes/python-tests.el: Add new test
`python-indent-dedent-line-backspace-4'.
---
 etc/NEWS                            |  7 +++++++
 lisp/progmodes/python.el            |  9 ++++++---
 test/lisp/progmodes/python-tests.el | 18 ++++++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index 8d41efdaf64..1ee573213aa 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1809,6 +1809,13 @@ restart Emacs.
 ---
 *** Support of 'electric-layout-mode' added.
 
+---
+*** DEL now deletes the text in the active region when point is between indentation.
+The command 'python-indent-dedent-line-backspace' (by default bound to
+'DEL') now deletes the text in the region and deactivates the mark if
+Transient Mark mode is enabled, the mark is active, and prefix argument
+is 1.
+
 ** Tmm Menubar
 
 ---
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index f4f0518dbfd..8b5ffae57d6 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1967,10 +1967,13 @@ python-indent-dedent-line
 
 (defun python-indent-dedent-line-backspace (arg)
   "De-indent current line.
-Argument ARG is passed to `backward-delete-char-untabify' when
-point is not in between the indentation."
+Argument ARG is passed to `backward-delete-char-untabify' when point is
+not in between the indentation or when Transient Mark mode is enabled,
+the mark is active, and ARG is 1."
   (interactive "*p")
-  (unless (python-indent-dedent-line)
+  (when (or
+         (and (use-region-p) (= arg 1))
+         (not (python-indent-dedent-line)))
     (backward-delete-char-untabify arg)))
 
 (put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)
diff --git a/test/lisp/progmodes/python-tests.el b/test/lisp/progmodes/python-tests.el
index 2c00f47d82c..d65ef39abb4 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -3780,6 +3780,24 @@ python-indent-dedent-line-backspace-3
                 (pos-bol) (pos-eol))
                "abcdef")))))
 
+(ert-deftest python-indent-dedent-line-backspace-4 ()
+  "Delete the text in the region instead of de-indentation.  Bug#48695."
+  (dolist (test '((1 4) (2 0)))
+    (python-tests-with-temp-buffer
+        "
+if True:
+    x ()
+    if False:
+"
+      (let ((current-prefix-arg (list (car test))))
+        (python-tests-look-at "if False:")
+        (end-of-line)
+        (transient-mark-mode)
+        (set-mark (point))
+        (backward-word 2)
+        (call-interactively #'python-indent-dedent-line-backspace)
+        (should (= (current-indentation) (cadr test)))))))
+
 (ert-deftest python-bob-infloop-avoid ()
   "Test that strings at BOB don't confuse syntax analysis.  Bug#24905"
   (python-tests-with-temp-buffer
-- 
2.49.1

Message #51 received at 48695 <at> debbugs.gnu.org (full text, mbox):

From: kobarity <kobarity <at> gmail.com>
To: Jakub Ječmínek <kuba <at> kubajecminek.cz>
Cc: mikpom <at> fastmail.com, Eli Zaretskii <eliz <at> gnu.org>, larsi <at> gnus.org,
 48695 <at> debbugs.gnu.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Mon, 28 Jul 2025 23:06:33 +0900

Jakub Ječmínek wrote:
> 
> kobarity <kobarity <at> gmail.com> writes:
> 
> > `python-indent-dedent-line-backspace-4' seems to fail in batch mode.
> > It would be better to use
> >
> >         (transient-mark-mode)
> >         (set-mark (point))
> >
> > instead of
> >
> >         (set-mark-command nil)
> 
> Oops, here's revised version. Thanks!

Thanks, it looks good to me.

Message #56 received at 48695-done <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: kuba <at> kubajecminek.cz, kobarity <kobarity <at> gmail.com>
Cc: mikpom <at> fastmail.com, 48695-done <at> debbugs.gnu.org, larsi <at> gnus.org
Subject: Re: bug#48695: [PATCH] Fix region deletion behavior in python.el
Date: Sat, 02 Aug 2025 17:16:48 +0300

> Date: Mon, 28 Jul 2025 23:06:33 +0900
> From: kobarity <kobarity <at> gmail.com>
> Cc: Eli Zaretskii <eliz <at> gnu.org>,
> 	mikpom <at> fastmail.com,
> 	larsi <at> gnus.org,
> 	48695 <at> debbugs.gnu.org
> 
> Jakub Ječmínek wrote:
> > 
> > kobarity <kobarity <at> gmail.com> writes:
> > 
> > > `python-indent-dedent-line-backspace-4' seems to fail in batch mode.
> > > It would be better to use
> > >
> > >         (transient-mark-mode)
> > >         (set-mark (point))
> > >
> > > instead of
> > >
> > >         (set-mark-command nil)
> > 
> > Oops, here's revised version. Thanks!
> 
> Thanks, it looks good to me.

Thanks, now installed on the master branch, and closing the bug.

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