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? ;) >>> 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? Thanks, -Stolee
