stringutil: add a new function to do minimal regex escaping
Per https://bugs.python.org/
issue29995, re.escape() used to
over-escape regular expression strings, but in Python 3.7 that's been
fixed, which also improved the performance of re.escape(). Since it's
both an output change for us *and* a perfomance win, let's just
effectively backport the new behavior to hg on all Python versions.
Differential Revision: https://phab.mercurial-scm.org/D3841
Create a repo, set the username to something more than 255 bytes, then run hg amend on it.
$ unset HGUSER
$ cat >> $HGRCPATH << EOF
> [ui]
> username = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <very.long.name@example.com>
> [extensions]
> amend =
> [experimental]
> evolution.createmarkers=True
> evolution.exchange=True
> EOF
$ hg init tmpa
$ cd tmpa
$ echo a > a
$ hg add
adding a
$ hg commit -m "Initial commit"
$ echo a >> a
$ hg amend 2>&1 | egrep -v '^(\*\*| )'
transaction abort!
rollback completed
Traceback (most recent call last):
*ProgrammingError: obsstore metadata value cannot be longer than 255 bytes (value "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <very.long.name@example.com>" for key "user" is 285 bytes) (glob)