[PATCH v4 0/7] Turn git add-i into built-in

This is the first version of a patch series to start porting git-add--interactive from Perl to C. Daniel Ferreira's patch series used as a head start: https://public-inbox.org/git/1494907234-28903-1-git-send-email-bnmvco@gmail.com/t/#u

Changes since v3:

 * add error check when calling add--helper's functions from
   git-add--interactive.perl
 * replace trailing whitespace in the test with variable $SP used in earlier
   tests

Cc: Phillip Wood phillip.wood@dunelm.org.uk [phillip.wood@dunelm.org.uk]

Daniel Ferreira (4):
  diff: export diffstat interface
  add--helper: create builtin helper for interactive add
  add-interactive.c: implement status command
  add--interactive.perl: use add--helper --status for status_cmd

Slavica Djukic (3):
  add-interactive.c: implement show-help command
  t3701-add-interactive: test add_i_show_help()
  add--interactive.perl: use add--helper --show-help for help_cmd

 .gitignore                 |   1 +
 Makefile                   |   2 +
 add-interactive.c          | 263 +++++++++++++++++++++++++++++++++++++
 add-interactive.h          |  10 ++
 builtin.h                  |   1 +
 builtin/add--helper.c      |  43 ++++++
 diff.c                     |  36 ++---
 diff.h                     |  18 +++
 git-add--interactive.perl  |  17 +--
 git.c                      |   1 +
 t/t3701-add-interactive.sh |  24 ++++
 11 files changed, 381 insertions(+), 35 deletions(-)
 create mode 100644 add-interactive.c
 create mode 100644 add-interactive.h
 create mode 100644 builtin/add--helper.c

base-commit: b21ebb671bb7dea8d342225f0d66c41f4e54d5ca
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-103%2FslavicaDj%2Fadd-i-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-103/slavicaDj/add-i-v4
Pull-Request: https://github.com/gitgitgadget/git/pull/103

Range-diff vs v3:

 1:  737767b6f4 = 1:  737767b6f4 diff: export diffstat interface
 2:  91b1963125 = 2:  91b1963125 add--helper: create builtin helper for interactive add
 3:  d247ef69fe = 3:  d247ef69fe add-interactive.c: implement status command
 4:  4950c889aa ! 4:  fb3f9378ac add--interactive.perl: use add--helper --status for status_cmd
     @@ -2,12 +2,21 @@
      
          add--interactive.perl: use add--helper --status for status_cmd
      
     -    Call the newly introduced add--helper builtin on
     +    Call the newly introduced add--helper builtin in
          status_cmd() instead of relying on add--interactive's Perl
     -    functions to build print the numstat.
     +    functions to print the numstat.
     +
     +    If an error occurs, it will be reported, but the Perl script will
     +    not exit, since the add--helper is called within an eval block.
     +
     +    As the Perl script will go away soon, so will this scenario, where
     +    the built-in helper is called  from the Perl script. Combined with
     +    the fact that it would be hard to test, we'll pass on adding
     +    a regression test for this.
      
          Signed-off-by: Daniel Ferreira <bnmvco@gmail.com>
          Signed-off-by: Slavica Djukic <slawica92@hotmail.com>
     +    Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
      
       diff --git a/git-add--interactive.perl b/git-add--interactive.perl
       --- a/git-add--interactive.perl
     @@ -19,7 +28,8 @@
      -	list_and_choose({ LIST_ONLY => 1, HEADER => $status_head },
      -			list_modified());
      -	print "\n";
     -+	system(qw(git add--helper --status));
     ++	my @status_cmd = ("git", "add--helper", "--status");
     ++	!system(@status_cmd) or die "@status_cmd exited with code $?";
       }
       
       sub say_n_paths {
 5:  581b108c9c = 5:  ab16afd1d5 add-interactive.c: implement show-help command
 6:  aede733318 ! 6:  0a27304a84 t3701-add-interactive: test add_i_show_help()
     @@ -7,6 +7,7 @@
          Also, add it before changing git-add--interactive.perl's help_cmd
          to demonstrate that there are no changes introduced by the
          conversion to C.
     +
          Prefix git add -i call with GIT_PAGER_IN_USE=true TERM=vt100
          to force colored output on Windows.
      
     @@ -21,7 +22,7 @@
       
      +test_expect_success 'show help from add--helper' '
      +	git reset --hard &&
     -+	cat >expect <<-\EOF &&
     ++	cat >expect <<-EOF &&
      +
      +	<BOLD>*** Commands ***<RESET>
      +	  1: <BOLD;BLUE>s<RESET>tatus	  2: <BOLD;BLUE>u<RESET>pdate	  3: <BOLD;BLUE>r<RESET>evert	  4: <BOLD;BLUE>a<RESET>dd untracked
     @@ -35,7 +36,7 @@
      +	<BOLD>*** Commands ***<RESET>
      +	  1: <BOLD;BLUE>s<RESET>tatus	  2: <BOLD;BLUE>u<RESET>pdate	  3: <BOLD;BLUE>r<RESET>evert	  4: <BOLD;BLUE>a<RESET>dd untracked
      +	  5: <BOLD;BLUE>p<RESET>atch	  6: <BOLD;BLUE>d<RESET>iff	  7: <BOLD;BLUE>q<RESET>uit	  8: <BOLD;BLUE>h<RESET>elp
     -+	<BOLD;BLUE>What now<RESET>> 
     ++	<BOLD;BLUE>What now<RESET>>$SP
      +	Bye.
      +	EOF
      +	test_write_lines h | GIT_PAGER_IN_USE=true TERM=vt100 git add -i >actual.colored &&
 7:  b9a1a7e37a ! 7:  ca2a7c4375 add--interactive.perl: use add--helper --show-help for help_cmd
     @@ -5,7 +5,15 @@
          Change help_cmd sub in git-add--interactive.perl to use
          show-help command from builtin add--helper.
      
     +    If an error occurs, it will be reported, but the Perl script will
     +    not exit, since the add--helper is called within an eval block.
     +
     +    Just like the change where the Perl script calls the add--helper
     +    to print the numstat, also here we forgo adding a regression test:
     +    the Perl script is on its way out (and this patch is part of that journey).
     +
          Signed-off-by: Slavica Djukic <slawica92@hotmail.com>
     +    Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
      
       diff --git a/git-add--interactive.perl b/git-add--interactive.perl
       --- a/git-add--interactive.perl
     @@ -24,7 +32,8 @@
      -diff          - view diff between HEAD and index
      -add untracked - add contents of untracked files to the staged set of changes
      -EOF
     -+	system(qw(git add--helper --show-help));
     ++	my @help_cmd = ("git", "add--helper", "--show-help");
     ++	!system(@help_cmd) or die "@help_cmd exited with code $?";
       }
       
       sub process_args {