GNU bug report logs -
#51006
28.0.60; Slowness while navigating in inferior-python-mode
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Reported by: Simen Heggestøyl <simenheg <at> runbox.com>
Date: Mon, 4 Oct 2021 12:55:01 UTC
Severity: normal
Found in version 28.0.60
Fixed in version 29.1
Done: Lars Ingebrigtsen <larsi <at> gnus.org>
Bug is archived. No further changes may be made.
Full log
Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):
The following recipe makes Emacs freeze, starting from 'emacs -Q':
1. Type 'M-x run-python RET'.
2. In the inferior-python-mode buffer that pops up, insert the following:
{
"foo-1": "bar-1",
"foo-2": "bar-2",
"foo-3": "bar-3",
"foo-4": "bar-4",
"foo-5": "bar-5",
"foo-6": "bar-6",
"foo-7": "bar-7",
"foo-8": "bar-8",
"foo-9": "bar-9",
}
3. Navigate up and down inside this structure by running 'next-line' and
'previous-line' in quick succession, alternating between them.
4. The movement appears slower and slower, eventually freezing up Emacs.
I've observed this in Emacs 27.2 as well, so it doesn't seem new to
Emacs 28.
Here's the report from a quick profiling I did in Emacs 28:
13447 94% - python-shell-font-lock-post-command-hook
13444 94% - font-lock-ensure
13444 94% - #<compiled -0x19f3968dc99b6307>
13444 94% - font-lock-fontify-region
13444 94% - font-lock-default-fontify-region
13420 94% - font-lock-fontify-syntactically-region
13420 94% - python-font-lock-syntactic-face-function
13412 94% - python-info-docstring-p
13396 94% + python-nav-beginning-of-statement
4 0% + python-info-assignment-statement-p
8 0% + font-lock-fontify-keywords-region
3 0% + font-lock-mode
529 3% + ...
183 1% + command-execute
This bug report was last modified 2 years and 337 days ago.
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