bug#23616: 25.0.94; TAB in inferior-python-mode

bug#23616: 25.0.94; TAB in inferior-python-mode

[Stephen Berman]

Doing the following (in either emacs-25 or master):

0. emacs -Q
1. M-x run-python
2. at the Python prompt type `for i in range(10):' then `RET', `TAB',
   `print i,', `RET'

results in this Python error:

IndentationError: expected an indented block

although the TAB in step 2 above visibly indents the line `print i,'.
If instead of `TAB' I type `SPC SPC SPC SPC' then after the final RET
the output is as expected:

0 1 2 3 4 5 6 7 8 9

It's not clear to me whether the above error indicates a bug in
python.el; is there some setting I haven't found that makes TAB work in
inferior-python-mode?  (In case it matter, this is with python 2.7.8., I
haven't tried with python3.)  I note that the definition of python-mode
has this line:

(set (make-local-variable 'indent-tabs-mode) nil)

which the definition of inferior-python-mode lacks; adding that line to
latter does make TAB work as I expect.  But I'm not sure whether this
setting is missing on purpose (but if so, why?).


In GNU Emacs 25.0.94.1 (x86_64-suse-linux-gnu, GTK+ Version 3.14.15)
 of 2016-05-18 built on rosalinde
Repository revision: 3b5e38cde194c4faa3865aa437b4a2749946c24d
Windowing system distributor 'The X.Org Foundation', version 11.0.11601000
System Description:	openSUSE 13.2 (Harlequin) (x86_64)

Configured using:
 'configure --with-xwidgets 'CFLAGS=-Og -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GCONF GSETTINGS NOTIFY
GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS
GTK3 X11 XWIDGETS

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

bug#23616: 25.0.94; TAB in inferior-python-mode

[Glenn Morris]

Of course it's a bug.
It works fine in 24.5 with tabs or spaces.
The error I get seems like it is related to the python completion code.
The least we should do is work around the issue by setting
indent-tabs-mode to nil in inferior python buffers too.
But IMO it should work with either.
(Eg for me in ipython, TAB inserts a literal tab, not spaces.)

bug#23616: 25.0.94; TAB in inferior-python-mode

[Stephen Berman]

On Tue,  7 Jun 2016 22:26:40 +0000 (UTC) rgm@gnu.org (Glenn Morris) wrote:

> branch: emacs-25
> commit ba3f206239349b725a970c7015f7f4ee8631ef6d
> Author: Glenn Morris <rgm@gnu.org>
> Commit: Glenn Morris <rgm@gnu.org>
>
>     * lisp/progmodes/python.el (inferior-python-mode):
>     Avoid tabs.  (Bug#23616)
> ---
>  lisp/progmodes/python.el |    1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
> index 2d22bb2..41d3e1c 100644
> --- a/lisp/progmodes/python.el
> +++ b/lisp/progmodes/python.el
> @@ -2678,6 +2678,7 @@ variable.
>  \(Type \\[describe-mode] in the process buffer for a list of commands.)"
>    (when python-shell--parent-buffer
>      (python-util-clone-local-variables python-shell--parent-buffer))
> +  (set (make-local-variable 'indent-tabs-mode) nil)
>    ;; Users can interactively override default values for
>    ;; `python-shell-interpreter' and `python-shell-interpreter-args'
>    ;; when calling `run-python'.  This ensures values let-bound in

Thanks, that satisfies me, so I'm closing this bug.

Steve Berman

bug#23616: 25.0.94; TAB in inferior-python-mode

[Glenn Morris]

Stephen Berman wrote:

> Thanks, that satisfies me, so I'm closing this bug.

As I said, IMO it should work with either tabs or spaces, as it used to
in previous releases. This change is only a workaround.

bug#23616: 25.0.94; TAB in inferior-python-mode

[Stephen Berman]

On Wed, 08 Jun 2016 11:39:42 -0400 Glenn Morris <rgm@gnu.org> wrote:

> Stephen Berman wrote:
>
>> Thanks, that satisfies me, so I'm closing this bug.
>
> As I said, IMO it should work with either tabs or spaces, as it used to
> in previous releases. This change is only a workaround.

Oh, ok, then feel free to reopen the bug.

Steve Berman