Subject: bug#54663: 29.0.50; align-current changed behavior

From: Henri Menke <[email-masked]>
Date: Fri, 01 Apr 2022 02:37:27 +0000

Somewhere between version 27.1 and 29.0.50 the `align' command changed
its behavior. Examples below are executed in emacs -Q.

Consider the following file `test.tex':

   \documentclass{article}
   \begin{document}
   \begin{tabular}{lr}
     abc def & zzz \\
     foo & bar \\
   \end{tabular}
   \end{document}

Opening this file in 27.1 and using M-x align-current yields the
expected

   \documentclass{article}
   \begin{document}
   \begin{tabular}{lr}
     abc def & zzz \\
     foo     & bar \\
   \end{tabular}
   \end{document}

but opening the file in 29.0.50 and using M-x align-current produces
something weird:

   \documentclass{article}
   \begin{document}
   \begin{tabular}{lr}
    abc def   & zzz \\
    foo & bar \\
   \end{tabular}
   \end{document}

There is only a single space of indentation and alignment is now at
spaces instead of & and \\ as expected for align-tex-modes.

;;===================
In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.30, cairo version 1.16.0)
Repository revision: 6f973faa912a5ac1ba643c6f5deb0c02baa0ba6d
Repository branch: master
System Description: NixOS 21.11 (Porcupine)

Configured using:
 'configure
 --prefix=/nix/store/b65vgqd1kdfxaly3y3yn3f3qkcrbdkwq-emacs-pgtkgcc-20220330.0
 --disable-build-details --with-modules --with-x-toolkit=gtk3
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Configured features:
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PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS XIM GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: LaTeX

Minor modes in effect:
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  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
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native-compile emacs)

Memory information:
((conses 16 85785 5008)
 (symbols 48 7342 0)
 (strings 32 23176 1221)
 (string-bytes 1 811910)
 (vectors 16 16616)
 (vector-slots 8 331153 7610)
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