Re: [PATCH v3] subtree: validate --prefix against commit in split

From: Josh Steadmon <steadmon@google.com>
Date: Feb 2, 2026, 18:54 UTC
Message-ID: <7k7ewvrb5hj3jyesiigy6dvo5w5pl67rk7ihztsuxbtqpymafv@ey64nvhzhacg>
In-Reply-To: <20260115175403.3971-3-pushkarkumarsingh1970@gmail.com>

On 2026.01.15 17:52, Pushkar Singh wrote:

Show 16 quoted lines

> git subtree split currently validates --prefix against the working tree.
> This breaks when splitting an older commit or when the working tree does
> not contain the subtree, even though the commit does.
> 
> For example:
> 
>   git subtree split --prefix=pkg <commit>
> 
> fails if pkg was removed later, even though it exists in <commit>.
> 
> Fix this by validating the prefix against the specified commit using
> git ls-tree instead of the working tree.
> 
> Add a test to ensure this behavior does not regress.
> 
> Signed-off-by: Pushkar Singh <pushkarkumarsingh1970@gmail.com>

Unfortunately, it seems this patch breaks the subtree tests. We noticed a failure in our build system at $WORK, and I was able to bisect the failure to this commit:

$ git bisect start 54b18a3513eed9ed5ced5c238ade55a434fd619a 66b2238f5c17644ddf15f75a53c76faeca6d9f1e $ git bisect run sh -c 'make && make -C contrib/subtree && make -C contrib/subtree test'

The tests fail on case 17 - split requires path given by option --prefix must exist.