[PATCH 0/7] add -i: close some regression test gaps

While re-implementing git add -i and git add -p in C, I tried to make sure that there is test coverage for all of the features I convert from Perl to C, to give me some confidence in the correctness from running the test suite both with GIT_TEST_ADD_I_USE_BUILTIN=true and with GIT_TEST_ADD_I_USE_BUILTIN=false.

However, I discovered that there are a couple of gaps. This patch series intends to close them.

The first patch might actually not be considered a gap by some: it basically removes the need for the TTY prerequisite in the git add -i tests to verify that the output is colored all right. This change is rather crucial for me, though: on Windows, where the conversion to a built-in shows the most obvious benefits, there are no pseudo terminals (yet), therefore git.exe cannot work with them (even if the MSYS2 Perl interpreter used by Git for Windows knows about some sort of pty emulation). And I really wanted to make sure that the colors work on Windows, as I personally get a lot out of those color cues.

The patch series ends by addressing two issues that are not exactly covering testing gaps:

 * While adding a test case, I noticed that git add -p exited with success 
   when it could not even generate a diff. This is so obviously wrong that I
   had to fix it right away (I noticed, actually, because my in-progress
   built-in git add -p failed, and the Perl version did not), and I used the
   same test case to verify that this is fixed once and for all.
   
   
 * While working on covering those test gaps, I noticed a problem in an
   early version of the built-in version of git add -p where the git apply
   --allow-overlap mode failed to work properly, for little reason, and I
   fixed it real quick.
   
   It would seem that the --allow-overlap function is not only purposefully
   under-documented, but also purposefully under-tested, probably to
   discourage its use. I do not quite understand the aversion to that
   option, but I did not feel like I should put up a battle here, so I did
   not accompany this fix with a new test script.
   
   In the end, the built-in version of git add -p does not use the 
   --allow-overlap function at all, anyway. Which should make everybody a
   lot happier.

Johannes Schindelin (7):
  t3701: add a test for advanced split-hunk editing
  t3701: avoid depending on the TTY prerequisite
  t3701: add a test for the different `add -p` prompts
  t3701: verify the shown messages when nothing can be added
  t3701: verify that the diff.algorithm config setting is handled
  git add -p: use non-zero exit code when the diff generation failed
  apply --allow-overlap: fix a corner case

 apply.c                    | 10 +++++
 git-add--interactive.perl  |  8 ++--
 t/t3701-add-interactive.sh | 90 ++++++++++++++++++++++++++++++++++----
 3 files changed, 97 insertions(+), 11 deletions(-)

base-commit: 2e697ced9d647d6998d70f010d582ba8019fe3af
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-172%2Fdscho%2Fadd-i-fixes-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-172/dscho/add-i-fixes-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/172