bug#61189: 29.0.60; Strange log-edit-mode M-q bug introduced in 27.1

[Eric Gillespie]

Eli Zaretskii <eliz@gnu.org> writes:

> It's because of the parenthesized "(e.g. bork)" thingy.

Right.  I didn't strip it out of my minimal test case because it
is essential.

Obviously, it was an actual parenthetical emacs broke the day I
encountered the bug.  I was curious if I could find the commit
where this actually happened to me...  and I did!

Unfortunately, it's a private repository, but if you want a
real-world example, here you go:

#+begin_example
Fix RPM upload.

More fallout from the deduplication.  I mistakenly put the os name
(e.g. 'centos') rather than major number (7) in the previous "fix".
#+end_example

You don't even need to mess with 'Summary:' or log-edit-hook; I
wish I hadn't brought those up.

Just move point into that second paragraph and then M-q

In addition to the strange space-deletion and colon-insertion, I
see now that M-q shouldn't be doing anything at all to this
paragraph.  My fill-column is 72 and those lines are already
filled as is...

Thanks!