Re: git-prompt.sh incompatible with non-basic global grep.patternType

[Richard Soderberg <rsoderberg@gmail.com>]

Aha! Yes, this works precisely as intended: the prompt works
correctly, and quickly, with this change in place.

 - R.

On Tue, Jul 19, 2016 at 4:24 AM, Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
> Hi Richard,
>
> On Mon, 18 Jul 2016, Richard Soderberg wrote:
>
>> Hi, I wanted to report something interesting that I found while tracing
>> a severe slowdown in git-prompt.sh.
>>
>> https://github.com/git/git/commit/6d158cba282f22fa1548af1188f78042fed30aed#diff-f37c4f4a898819f0ca4b5ff69e81d4d9R141
>>
>> Way back in this commit, someone added a useful chunk of code that works
>> perfectly with svn+ssh:// URLs under basic regexes:
>>
>> + local svn_upstream=($(git log --first-parent -1 \ +
>> --grep="^git-svn-id: \(${svn_url_pattern:2}\)" 2>/dev/null))
>>
>> However, if I switch over to Perl regexes (or Extended):
>>
>> git config --global grep.patternType perl
>>
>> Then the command runs for one wall clock second and shows incorrect
>> results on my repository. I eventually traced this to an issue with the
>> regular expression provided, assuming the svn repository url is
>> "svn+ssh://...":
>>
>> git log ... --grep="^git-svn-id: \(svn+ssh://...\)" 2>/dev/null
>>
>> The + sign isn't escaped in git-prompt.sh, which under non-basic regexes
>> causes the match to fail entirely.
>>
>>  - R.
>>
>> ps. git log --basic-regexp does not fix the issue, as for unknown
>> reasons (I'll start another thread) the command-line option doesn't
>> override grep.patternType.
>
> Maybe this helps?
>
> -- snipsnap --
> diff --git a/contrib/completion/git-prompt.sh
> b/contrib/completion/git-prompt.sh
> index 97eacd7..74be907 100644
> --- a/contrib/completion/git-prompt.sh
> +++ b/contrib/completion/git-prompt.sh
> @@ -143,7 +143,7 @@ __git_ps1_show_upstream ()
>                 # get the upstream from the "git-svn-id: ..." in a commit
>                 # message
>                 # (git-svn uses essentially the same procedure internally)
>                 local -a svn_upstream
> -               svn_upstream=($(git log --first-parent -1 \
> +               svn_upstream=($(git -c grep.patternType=default log --first-parent -1 \
>                                         --grep="^git-svn-id: \(${svn_url_pattern#??}\)" 2>/dev/null))
>                 if [[ 0 -ne ${#svn_upstream[@]} ]]; then
>                         svn_upstream=${svn_upstream[${#svn_upstream[@]} - 2]}
>