RE: Bug: 'git stash --staged' crashes with binary files

[<rsbecker@nexbridge.com>]

On Wednesday, October 11, 2023 2:18 PM, Peff wrote:
>On Thu, Jun 01, 2023 at 10:26:13PM +0100, Adam Johnson wrote:
>
>> Stage a binary file and run 'git stash --staged'. The stash is created
>> but the command fails to remove changes from the index:
>>
>> $ echo -n "\0" >file
>>
>> $ git add file
>>
>> $ git stash --staged
>> Saved working directory and index state WIP on main: e7911b6 Whatever
>> error: cannot apply binary patch to 'file' without full index line
>> error: file: patch does not apply
>> Cannot remove worktree changes
>>
>> $ git status
>> ...
>> Changes to be committed:
>>         new file:   file
>>
>> The "remove from the index" step seems not to be binary-compatible.
>
>This seems like a bug. It looks like stash does pass "--binary" in some cases, but not
>all. So it's probably a matter of finding the right invocation and adding it.
>
>> The below patch adds a reproducing test.
>
>I think finding the bug and writing the test is probably 75% of the work. :)
>
>> diff --git t/t3903-stash.sh t/t3903-stash.sh index
>> 376cc8f4ab..5e3ea64f38 100755
>> --- t/t3903-stash.sh
>> +++ t/t3903-stash.sh
>> @@ -392,6 +392,13 @@ setup_stash()
>>      git stash pop &&
>>      test bar,bar4 = $(cat file),$(cat file2)  '
>> +test_expect_success 'stash --staged with binary file' '
>> +    echo -n "\0" >file &&
>
>Unfortunately "echo -n" isn't portable. But you can use:
>
>  printf "\0" >file
>
>instead.
>
>> +    git add file &&
>> +    git stash --staged &&
>> +    git stash pop &&
>> +    test "\0" = $(cat file)
>> +'
>
>I doubt this "test" will work, as the shell won't interpolate that into a NUL (and
>anyway, I think having NULs in shell variables isn't portable). You could perhaps do:
>
>  printf "\0" >expect &&
>  test_cmp expect file

Agreed. The specific test construct does not appear portable, but piping printf "\0" to expect works.
/home/randall: test "\0" != `printf "\0"`
bash: warning: command substitution: ignored null byte in input
bash: test: \0: unary operator expected

--Randall