On Tue, Nov 17, 2020 at 08:56:16AM -0500, Derrick Stolee wrote: > > On 11/16/2020 8:07 PM, Emily Shaffer wrote: > > On Mon, Nov 16, 2020 at 04:40:35PM -0800, Junio C Hamano wrote: > >> > >> Emily Shaffer <emilyshaffer@xxxxxxxxxx> writes: > >> > >>> Because 'git maintenance unregister' spins a child process to call 'git > >>> config --unset maintenance.repo <cwd>', it actually fails if "cwd" > >>> contains a POSIX regular expression special character: > >>> > >>> git config [<file-option>] --unset name [value_regex] > >> > >> Good find. And it is even worse that value_regex uses ERE, not BRE, > >> which means even an otherwise innocuous letter like '+' cannot be > >> used without quoting. > > > > I should have mentioned in the first letter than Jonathan Nieder was the > > one who made the jump from "this is breaking in the buildbot but not > > locally" to regular expression metachars. Credit where it's due. > > Thank you for finding and reporting this bug. > > Can I at least have a short moment of griping about anyone putting > regex characters into their directory names? ;) In this case the directory name contained 'git-2.29.2+next.20201112' - so I'll leave it up to you to decide ;) ;) > > >>> You can demo it for yourself like so: > >>> > >>> git init repro+for+maintenance > >>> git maintenance register > >>> git maintenance unregister > >>> echo $? # returns '5' > >>> git config --list --global > >>> > >>> I see two paths forward: > >>> > >> > >> 0. Quote the value_regex properly, instead of blindly using a value > >> that comes from the environment. > > Pulling the subcommand from my test enfironment using GIT_TRACE2_PERF=1 > I see the following quotes being used: > > git config --global --unset maintenance.repo "/repos/new+repo*test" > > I'm guessing that what we really want is to _escape_ the regex glob > characters? This command works: > > git config --global --unset maintenance.repo "/repos/new\+repo\*test" > > The only place I see where we do that currently is in > builtin/sparse-checkout.c:escaped_pattern(). Please let me know if > you know of a more suitable way to escape regex characters. > > >>> 1. Teach 'git config' to learn either which regex parser to use > >>> (including fixed), or at least to learn "value isn't a regex", or > >>> > >>> 2. Don't spin a child process in 'git maintenance [un]register' and > >>> instead just call the config API. > >> > >>> I'd suggest #2. The config API is very nice, and seems to have a simple > >>> way to add or remove configs to your global file in just a couple of > >>> lines. If there's a reason why it's not simpler to do it that way, it's > >>> my fault for missing the review :) > >> > >> My short-to-mid-term preference is to do #1 to allow a value to be > >> spelled literally (i.e. remove entry with _this_ value, and add this > >> one instead), and optionally do #2 as an optimization that is not > >> essential. I do not offhand know how you can make #2 alone fly > >> without doing some form of #1, as I think the same value_regex that > >> ought to be ERE to specify entries to be replaced needs to be used > >> under the cover even if you use "config API" anyway. > > > > Ah, right you are - I had figured the regex parsing was done earlier, > > but it indeed looks to happen in > > config.c:git_config_set_multivar_in_file_gently. Thanks. > > So the "real fix" is to allow a command-line option to 'git config' > that makes the "value_regex" parameter a literal string? Of course, > this would either require wiring an option down into > git_config_set_multivar_in_file_gently() to treat the string as a > literal _or_ to escape the input string in builtin/config.c. > > Am I understanding the intended plan here? That fix sounds like something I would want anyways - the ability to choose the regex style just like we can for 'git grep' (and I think for other tools which I'm having trouble finding now). - Emily
