From: Phillip Wood <phillip.wood@talktalk.net>
Date: Sat, 31 Mar 2018 16:26:22 GMT
Subject: Re: [PATCH v2] add -p: fix 2.17.0-rc* regression due to moved code
Message-ID: <f60a2014-3b02-3eae-76cb-950330113afa@talktalk.net>
In-Reply-To: <20180331125058.4506-1-avarab@gmail.com>

On 31/03/18 13:50, Ævar Arnfjörð Bjarmason wrote:
> Fix a regression in 88f6ffc1c2 ("add -p: only bind search key if
> there's more than one hunk", 2018-02-13) which is present in
> 2.17.0-rc*, but not 2.16.0.
> 
> In Perl, regex variables like $1 always refer to the last regex
> match. When the aforementioned change added a new regex match between
> the old match and the corresponding code that was expecting $1, the $1
> variable would always be undef, since the newly inserted regex match
> doesn't have any captures.
> 
> As a result the "/" feature to search for a string in a hunk by regex
> completely broke, on git.git:

Good catch, I could have sworn I'd tested my patch but I obviously 
didn't notice the warning (I've got interactive.singlekey set so it 
prints the warning and then prompts as it always has done). Calling it 
completely broken is perhaps a little harsh as it does work if you enter 
the regex again and with interactive.singlekey set you only have to 
enter the regex once.

Thanks for fixing it

Phillip
> 
>      $ perl -pi -e 's/Git/Tig/g' README.md
>      $ ./git --exec-path=$PWD add -p
>      [..]
>      Stage this hunk [y,n,q,a,d,j,J,g,/,s,e,?]? s
>      Split into 4 hunks.
>      [...]
>      Stage this hunk [y,n,q,a,d,j,J,g,/,s,e,?]? /Many
>      Use of uninitialized value $1 in string eq at /home/avar/g/git/git-add--interactive line 1568, <STDIN> line 1.
>      search for regex? Many
> 
> I.e. the initial "/regex" command wouldn't work, and would always emit
> a warning and ask again for a regex, now it works as intended again.
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
> 
> Of course I just noticed the grammar errors in the commit message
> after sending. Here's a v2 with that fixed, also genreated the patch
> with -U6 to make it clear what's going on.
> 
>   git-add--interactive.perl | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/git-add--interactive.perl b/git-add--interactive.perl
> index d190469cd8..c1f52e457f 100755
> --- a/git-add--interactive.perl
> +++ b/git-add--interactive.perl
> @@ -1561,13 +1561,13 @@ sub patch_update_file {
>   			elsif ($line =~ m|^/(.*)|) {
>   				my $regex = $1;
>   				unless ($other =~ m|/|) {
>   					error_msg __("No other hunks to search\n");
>   					next;
>   				}
> -				if ($1 eq "") {
> +				if ($regex eq "") {
>   					print colored $prompt_color, __("search for regex? ");
>   					$regex = <STDIN>;
>   					if (defined $regex) {
>   						chomp $regex;
>   					}
>   				}
>