Bug when stashing previously-ignored file plus associated .gitignore change

> If calling git stash -u on a repo that contains a file that is not
> ignored any more due to a current modification of the gitignore file,
> this file is stashed but not remove from the working tree.
> This is due to git-stash first doing a reset --hard which clears the
> .gitignore file modification and the call git clean, leaving the file
> untouched.
> This causes git stash pop to fail due to the file existing.
>
> This patch simply switches the order between cleaning and resetting
> and adds a test for this usecase.
>
> Signed-off-by: Nicolas Morey-Chaisemartin <nicolas@morey-chaisemartin.com>
> Reported-by: Sam Partington <sam@whiteoctober.co.uk>

> ---
>  git-stash.sh                       | 11 ++++++-----
>  t/t3905-stash-include-untracked.sh | 18 ++++++++++++++++++
>  2 files changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/git-stash.sh b/git-stash.sh
> index 9b6c2da7b..39083b4d9 100755
> --- a/git-stash.sh
> +++ b/git-stash.sh
> @@ -300,6 +300,12 @@ push_stash () {
>  
>  	if test -z "$patch_mode"
>  	then
> +		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
> +		if test -n "$untracked"
> +		then
> +			git clean --force --quiet -d $CLEAN_X_OPTION -- "$@"
> +		fi
> +
>  		if test $# != 0
>  		then
>  			git reset -q -- "$@"
> @@ -309,11 +315,6 @@ push_stash () {
>  		else
>  			git reset --hard -q
>  		fi
> -		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
> -		if test -n "$untracked"
> -		then
> -			git clean --force --quiet -d $CLEAN_X_OPTION -- "$@"
> -		fi
>  
>  		if test "$keep_index" = "t" && test -n "$i_tree"
>  		then
> diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
> index 193adc7b6..c1f84d3d5 100755
> --- a/t/t3905-stash-include-untracked.sh
> +++ b/t/t3905-stash-include-untracked.sh
> @@ -211,4 +211,22 @@ test_expect_success 'stash push with $IFS character' '
>  	test_path_is_file bar
>  '
>  
> +cat > .gitignore <<EOF
> +ignored
> +ignored.d/*
> +EOF
> +
> +test_expect_success 'stash previously ignored file' '
> +which git &&

> +	git reset HEAD &&
> +	git add .gitignore &&
> +	git commit -m "Add .gitignore" && 
> +	>ignored.d/foo &&
> +	echo "!ignored.d/foo" >> .gitignore &&
> +	git stash save --include-untracked &&
> +	test_path_is_missing ignored.d/foo &&
> +	git stash pop &&
> +	test_path_is_file ignored.d/foo
> +'
> +
>  test_done

> Hi there,
> 
> I'm running git 2.7.4 on Ubuntu 16.04.  I've found a couple of
> problems when "un-ignoring" files in tandem with git stash.
> 
> Here's how to reproduce:
> 
> Say you have a project using git, with a .gitignore file which
> contains the following line:
> 
> bin/*
> 
> You can then see the problems by doing this:
> 
> $ touch bin/mynewfile # this file will be ignored at this point > 
> and then updating .gitignore to look like this (adding that second line):
> 
> bin/*
> !bin/mynewfile
> 
> So far, so good; the new file is no longer ignored.
> 
> But now, try stashing the changes and including untracked files in the stash:
> 
> $ git stash save -u
> 
> Here's the first problem, bin/mynewfile is still there:
> 
> $ ls bin/mynewfile
> bin/mynewfile
> 
> But you'd expect it to not be there and be in the stash, I think.
> This is what would normally happen with the untracked-files option for
> git stash.
> 
> This leads to the second problem - you can't now pop the stash:
> 
> $ git stash pop
> bin/mynewfile already exists, no checkout
> Could not restore untracked files from stash
> 
> If you want to apply the stash, you have to remove the file:
> 
> $ rm bin/mynewfile
> $ git stash pop # this works, and re-creates bin/mynewfile
> 
> This is quite an unusual edge case, but I have hit it two or three
> times now and so thought it worth reporting, but I'll understand if
> it's deemed not worth fixing!
> 
> Do let me know if you need any more information from me here.
> 
> Thanks
> Sam
> 
> PS Sorry for the lack of formatting - I'm sending this as plain text
> as my original HTML emails was rejected as possible spam by your
> mailserver.
> 
> Sam Partington
> Senior Developer
> 

> On Fri, Aug 11, 2017 at 04:55:38PM +0100, Sam Partington wrote:
>> Hi there,
>>
>> I'm running git 2.7.4 on Ubuntu 16.04.  I've found a couple of
>> problems when "un-ignoring" files in tandem with git stash.
>>
>> Here's how to reproduce:
>>
>> Say you have a project using git, with a .gitignore file which
>> contains the following line:
>>
>> bin/*
>>
>> You can then see the problems by doing this:
>>
>> $ touch bin/mynewfile # this file will be ignored at this point >
>> and then updating .gitignore to look like this (adding that second line):
>>
>> bin/*
>> !bin/mynewfile
>>
>> So far, so good; the new file is no longer ignored.
>>
>> But now, try stashing the changes and including untracked files in the stash:
>>
>> $ git stash save -u
>>
>> Here's the first problem, bin/mynewfile is still there:
>>
>> $ ls bin/mynewfile
>> bin/mynewfile
>>
>> But you'd expect it to not be there and be in the stash, I think.
>> This is what would normally happen with the untracked-files option for
>> git stash.
>>
>> This leads to the second problem - you can't now pop the stash:
>>
>> $ git stash pop
>> bin/mynewfile already exists, no checkout
>> Could not restore untracked files from stash
>>
>> If you want to apply the stash, you have to remove the file:
>>
>> $ rm bin/mynewfile
>> $ git stash pop # this works, and re-creates bin/mynewfile
>>
>> This is quite an unusual edge case, but I have hit it two or three
>> times now and so thought it worth reporting, but I'll understand if
>> it's deemed not worth fixing!
>>
>> Do let me know if you need any more information from me here.
>>
>> Thanks
>> Sam
>>
>> PS Sorry for the lack of formatting - I'm sending this as plain text
>> as my original HTML emails was rejected as possible spam by your
>> mailserver.
>>
>> Sam Partington
>> Senior Developer
>>
>
> Hello Sam,
>
> Is it the case that you did not commit the addition of '!bin/mynewfile'
> yet? I suspect that by running git stash save -u, you also are stashing
> this addition to the .gitigore file. Can you confirm this?
>
> Kevin