git_checkout_index doesn't respect GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH checkout parameter

[lapfelix]

Reproduction steps

Use git_checkout_index to checkout multiple modified files (where we want to revert the changes that were made) with the GIT_CHECKOUT_DISABLE_PATHSPEC_MATCH flag enabled in the checkout_strategy where the files all have the same prefix as other modified files.

For example, I modified test9.txt, test10.txt, test11.txt and test12.txt and I want to discard the changes from test10.txt and test11.txt by using git_checkout_index.

Expected behavior

Only the files specified in the git_checkout_options's paths should be checked out.

In my example, that would be only test10.txt and test11.txt.

Actual behavior

All of the files with the same prefix as the two checked out files have their changes discarded too.

In my example, the changes made to test12.txt would also be discarded because test12.txt has test1 as prefix.

I created a test case in checkout/index.c in a branch in my libgit2 fork that demonstrates the issue: f37c77b

Version of libgit2 (release number or SHA1)

5597517 (which is the latest commit on master).
Also reproduced on 15e1193 (which dates back from 2017)

Operating system(s) tested

macOS 10.15.2 (build 19C57)

[ethomson]

Thanks for opening the issue, and thanks especially for the helpful test case. That made it very easy to reproduce this issue and - ultimately - to understand it.

One note - your test was setting checkout pathspecs to test11.txt and test12.txt but was validating that test10.txt and test11.txt were the ones checked out. I modified the test case so that they match.

Should be fixed by #5378 - if you have other test criteria, could you test them against this patch?

[lapfelix]

Oh yes you're right about the test12.txt typo 🤦‍♂

I'll test the patch with GitUp, but if my test passes then it should be good!

Thanks a lot for the quick patch!