add -p: fix 2.17.0-rc* regression due to moved code

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: $ 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> Signed-off-by: Junio C Hamano <gitster@pobox.com>