[ESS-bugs] ess-mode 16.04 [git: cccb9481389b]; ess-noweb-font-lock-mode: emacs hangs using uncomment-region with math environments

[Braun, Michael]

Consider a file with a .Rnw extension, with a LaTeX major mode, and Noweb and NWFL minor modes. The uncomment-region command works fine with general text and text-like environments (e.g., itemize).  However, when calling uncomment-region on a region that includes a math environment (e.g., align, eqnarray), the entire emacs process hangs, requiring a Force Quit.  For example:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

On the following equation, try comment-region, and then uncomment-region. On my system, the uncomment-region call is what hangs the process.

\begin{align}
  1+1=2
\end{align}

\end{document}


This problem does not occur with Aquamacs 3.2, GNU Emacs 24.4.51.2. Although the system data below indicates ess version 16.04, the problem also occurs with ess version 16.10.

When I toggle ess-noweb-font-lock-mode off, the problem with uncomment-region disappears. So it looks like there is a problem with ess-noweb-font-lock-mode on either Emacs 25 (or the Aquamacs 3.3 distribution of it), or MacOS Sierra.  I don't know which.  Of course, disabling ess-noweb-font-lock-mode means that I lose the font-lock features.

Thanks,

Michael Braun
braunm at smu.edu



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(S): ess-s-versions-create making M-x defuns for 



Emacs  : Aquamacs 3.3  GNU Emacs 25.1.1 (x86_64-apple-darwin14.1.0, NS appkit-1344.72 Version 10.10.2 (Build 14C109))
of 2016-09-19 on 24a02dbf6b34ae061ef4df89f15bfbc5d3ed497e
Package: ess-mode 16.04 [git: cccb9481389b]

current state:
==============
(setq
ess-language "S"
ess-dialect "R"
ess-ask-for-ess-directory t
ess-ask-about-transfile nil
ess-directory nil
ess-keep-dump-files "always"
ess-source-directory "/var/folders/jf/24ry58qj0hd2n_qshf0qh2200000gp/T/"
ess-use-ido t
ess-use-eldoc t
ess-use-tracebug t
ess-use-auto-complete t
ess-use-company t
ess-eval-visibly-p t
ess-can-eval-in-background nil
ess-local-process-name nil
)