bug#61436: Emacs Freezing With Java Files

[Mats Lidell via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Hi Jens,

Thanks for the report. Seems non trivial.

> Jens Schmidt writes:
> Jens Schmidt <jschmidt4gnu@vodafonemail.de> writes:
>
> >   Ensure package "hyperbole" is installed.  (Its only role in this
> >   issue seems to be a "background load generator", but I'm not 100%
> >   sure here.)
>
> The second part above is not true!  Hyperbole mode is the culprit,
> unless proven otherwise.  Here is a 100%-freezing reproducer (with
> P1.java as from the initial post):
>
> ------------------------- init.el -------------------------
> (require 'package)
> (add-to-list 'package-archives
> 	     '("melpa" . "https://melpa.org/packages/"))
> (add-to-list 'package-archives
> 	     '("gnu" . "https://elpa.gnu.org/packages/"))
> (package-initialize)
> ;(setq hkey-init nil)
> (hyperbole-mode 1)
> ------------------------- init.el -------------------------
>
> Execute Emacs as:
>
>   ./src/emacs -Q -l ~/tmp/init.el +181 ~/tmp/P1.java
>
> That always freezes Emacs (29 and master) even before it has a chance to
> display P1.java.  The freeze happens in function
> `c-get-fallback-scan-pos', where the while loop inf-loops, BUT:
>
> If you uncomment the line setting `hkey-init' to nil in init.el and
> repeat: No freeze.

I have tried to recreate the freezing (with 29.1 running docker) and I don't
see the exact same behavior. For me P1.java is displayed and there us no
freeze but when I try to go to top or bottom of file it freezes and I have to
hit C-g. After that it seems to work. This is just an observation. There can
be more things affected of course.

I have tried both with the hyperbole stable and devel packages and get the
same behavior. 

Note: I don't know what P1.java means here. I have picked a java file at
random that I had on my machine that is large. Is P1.java a specific file that
has been shared earlier?

> Not sure how to continue here - since this is a GNU ELPA package, it can
> be further handled on Emacs debbugs, no?  Mats, Bob?

Hyperbole has its own tracker.

https://debbugs.gnu.org/cgi/pkgreport.cgi?package=hyperbole

%% Mats