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From: Mauricio Collares <mauricio@collares.org>
To: 46670@debbugs.gnu.org
Subject: bug#46670: 28.0.50; [feature/native-comp] possible miscompilation affecting lsp-mode
Date: Sat, 20 Feb 2021 21:12:11 -0300	[thread overview]
Message-ID: <87a6ry46uc.fsf@collares.org> (raw)


This was found by Anthony Cowley, who isolated the exact function in
lsp-mode that was misbehaving. I verified that I could reproduce this
findings, and then I removed surrounding context to obtain a minimized
testcase. If this fails to reproduce, it's entirely my fault.

Steps to reproduce:

1) Put this in minimized.el:

;;; -*- lexical-binding: t; -*-

(defun minimized--look-back (s)
  (and (equal (buffer-substring-no-properties (- (point) (length s)) (point))
              s)
       s))

(defun minimized-go ()
  (interactive)
  (message (minimized--look-back ".")))

(provide 'minimized)

2) Type "." in a buffer and then run minimized-go with the point after
the period. This prints back "." in the minibuffer if the code's
interpreted but not if it's native-compiled.

Note that removing the "lexical-binding: t" line makes the bug not
reproduce. Replacing "(- (point) (length s))" by "(1- (point))" also
makes the bug disappear.

Best,
Mauricio





             reply	other threads:[~2021-02-21  0:12 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-21  0:12 Mauricio Collares [this message]
2021-02-21 11:51 ` bug#46670: 28.0.50; [feature/native-comp] possible miscompilation affecting lsp-mode Pip Cet
2021-02-21 11:56   ` Pip Cet
2021-02-21 21:03     ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-21 22:46       ` Pip Cet
2021-02-22  9:37         ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-22 10:04           ` Pip Cet
2021-02-22 10:25             ` Pip Cet
2021-02-22 11:23               ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-22 12:11                 ` Pip Cet
2021-02-22 13:12                   ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23  7:59                     ` Pip Cet
2021-02-23  9:04                       ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23 23:26                         ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24  2:10                           ` Mauricio Collares
2021-02-24  8:22                             ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23 19:09                     ` Pip Cet
2021-02-23 23:36                       ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24  4:31                         ` Pip Cet
2021-02-24  9:04                           ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24  9:28                             ` Pip Cet
2021-02-24  9:42                               ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24  9:46                                 ` Pip Cet
2021-02-24 10:06                                   ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-25 12:41                                     ` Pip Cet
2021-02-25 14:58                                       ` Eli Zaretskii
2021-02-25 15:14                                         ` Pip Cet
2021-02-25 15:31                                           ` Eli Zaretskii
2021-02-25 16:56                                       ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-25 20:59                                         ` Pip Cet
2021-02-26 19:33                                           ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-26 20:30                                             ` Pip Cet
2021-02-26 20:44                                               ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-26 20:11                                           ` Eli Zaretskii
2021-02-26 20:32                                             ` Pip Cet
2021-02-27  5:06                                             ` Pip Cet
2021-02-27  7:49                                               ` Eli Zaretskii
2021-02-27  9:39                                                 ` Pip Cet
2021-02-27 10:24                                                   ` Eli Zaretskii
2021-02-27 12:39                                                     ` Pip Cet
2021-02-27 13:30                                                       ` Eli Zaretskii
2021-02-27 17:15                                                         ` Pip Cet
2021-02-27 18:40                                                           ` Eli Zaretskii
2021-02-28  8:14                                                             ` Pip Cet
2021-03-01  5:24                                                               ` Richard Stallman
2021-03-01  6:40                                                                 ` Pip Cet
2021-02-22 11:16             ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-23  9:07               ` Pip Cet
2021-02-23 22:55                 ` Andrea Corallo via Bug reports for GNU Emacs, the Swiss army knife of text editors
2021-02-24  7:00                   ` Pip Cet

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