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Author SHA1 Message Date
Junio C Hamano ec4f70e647 Merge branch 'pw/add-p-hunk-split-fix'
"git add -p" rewritten in C regressed hunk splitting in some cases,
which has been corrected.

* pw/add-p-hunk-split-fix:
  builtin add -p: fix hunk splitting
  t3701: clean up hunk splitting tests
2022-02-09 14:20:59 -08:00
Phillip Wood 7008ddc645 builtin add -p: fix hunk splitting
The C reimplementation of "add -p" fails to split the last hunk in a
file if hunk ends with an addition or deletion without any post context
line unless it is the last file to be processed.

To determine whether a hunk can be split a counter is incremented each
time a context line follows an insertion or deletion. If at the end of
the hunk the value of this counter is greater than one then the hunk
can be split into that number of smaller hunks. If the last hunk in a
file ends with an insertion or deletion then there is no following
context line and the counter will not be incremented. This case is
already handled at the end of the loop where counter is incremented if
the last hunk ended with an insertion or deletion. Unfortunately there
is no similar check between files (likely because the perl version
only ever parses one diff at a time). Fix this by checking if the last
hunk ended with an insertion or deletion when we see the diff header
of a new file and extend the existing regression test.

Reproted-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-12 10:29:53 -08:00
Ævar Arnfjörð Bjarmason 6def0ff878 run-command API users: use strvec_pushv(), not argv assignment
Migrate those run-command API users that assign directly to the "argv"
member to use a strvec_pushv() of "args" instead.

In these cases it did not make sense to further refactor these
callers, e.g. daemon.c could be made to construct the arguments closer
to handle(), but that would require moving the construction from its
cmd_main() and pass "argv" through two intermediate functions.

It would be possible for a change like this to introduce a regression
if we were doing:

      cp.argv = argv;
      argv[1] = "foo";

And changed the code, as is being done here, to:

      strvec_pushv(&cp.args, argv);
      argv[1] = "foo";

But as viewing this change with the "-W" flag reveals none of these
functions modify variable that's being pushed afterwards in a way that
would introduce such a logic error.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00
Ævar Arnfjörð Bjarmason 48ca53cac4 *.c static functions: add missing __attribute__((format))
Add missing __attribute__((format)) function attributes to various
"static" functions that take printf arguments.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-13 15:20:20 -07:00
Junio C Hamano e0d25686e3 Merge branch 'js/add-i-color-fix'
"git add -i" failed to honor custom colors configured to show
patches, which has been corrected.

* js/add-i-color-fix:
  add -i: verify in the tests that colors can be overridden
  add -p: prefer color.diff.context over color.diff.plain
  add -i (Perl version): color header to match the C version
  add -i (built-in): use the same indentation as the Perl version
  add -p (built-in): do not color the progress indicator separately
  add -i (built-in): use correct names to load color.diff.* config
  add -i (built-in): prevent the `reset` "color" from being configured
  add -i: use `reset_color` consistently
  add -p (built-in): imitate `xdl_format_hunk_hdr()` generating hunk headers
  add -i (built-in): send error messages to stderr
  add -i (built-in): do show an error message for incorrect inputs
2020-12-08 15:11:17 -08:00
Johannes Schindelin 6681e36032 add -p (built-in): do not color the progress indicator separately
The Perl version of this command colors the progress indicator and the
prompt message in one go.

Let's do the same in the built-in version so that the same upcoming test
(which will compare the output of `git add -p` against a known-good
version) will pass both for the Perl version as well as for the built-in
version.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 15:59:02 -08:00
Johannes Schindelin 6f1a5caa0b add -i: use `reset_color` consistently
We already maintain a list of colors in the `add_i_state`, therefore we
should use them.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 09:07:52 -08:00
Johannes Schindelin decc9ee4ea add -p (built-in): imitate `xdl_format_hunk_hdr()` generating hunk headers
In libxdiff, imitating GNU diff, the hunk headers only show the line
count if it is different from 1. When splitting hunks, the Perl version
of `git add -p` already imitates this. Let's do the same in the built-in
version of said command.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 09:07:52 -08:00
Junio C Hamano f3cfeb3078 Merge branch 'dl/checkout-p-merge-base'
"git checkout -p A...B [-- <path>]" did not work, even though the
same command without "-p" correctly used the merge-base between
commits A and B.

* dl/checkout-p-merge-base:
  t2016: add a NEEDSWORK about the PERL prerequisite
  add-patch: add NEEDSWORK about comparing commits
  Doc: document "A...B" form for <tree-ish> in checkout and switch
  builtin/checkout: fix `git checkout -p HEAD...` bug
2020-10-27 15:09:51 -07:00
Denton Liu f82a9e517f add-patch: add NEEDSWORK about comparing commits
The two versions of add-patch has special-casing for the literal
revision "HEAD". However, we want to handle other ways of saying "HEAD"
in the same way.[0] Add a NEEDSWORK to the add-patch code that does this
so that it can be addressed later.

[0]: https://lore.kernel.org/git/xmqqsgat7ttf.fsf@gitster.c.googlers.com/

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-07 09:49:06 -07:00
Junio C Hamano 458205ff0f Merge branch 'pw/add-p-edit-ita-path'
"add -p" now allows editing paths that were only added in intent.

* pw/add-p-edit-ita-path:
  add -p: fix editing of intent-to-add paths
2020-09-22 12:36:28 -07:00
Junio C Hamano 694e517778 Merge branch 'jk/add-i-fixes'
"add -i/-p" fixes.

* jk/add-i-fixes:
  add--interactive.perl: specify --no-color explicitly
  add-patch: fix inverted return code of repo_read_index()
2020-09-18 17:58:04 -07:00
Junio C Hamano 3ad8d3e4f9 Merge branch 'pw/add-p-leakfix'
Leakfix.

* pw/add-p-leakfix:
  add -p: fix memory leak
2020-09-18 17:58:03 -07:00
Phillip Wood 75a009dc29 add -p: fix editing of intent-to-add paths
A popular way of partially staging a new file is to run `git add -N
<path>` and then use the hunk editing of `git add -p` to select the
part of the file that the user wishes to stage. Since
85953a3187 ("diff-files --raw: show correct post-image of
intent-to-add files", 2020-07-01) this has stopped working as
intent-to-add paths are now show as new files rather than changes to
an empty blob and `git apply` refused to apply a creation patch for a
path that was marked as intent-to-add. 7cfde3fa0f ("apply: allow "new
file" patches on i-t-a entries", 2020-08-06) fixed the problem with
apply but it still wasn't possible to edit the added hunk properly.

2c8bd8471a ("checkout -p: handle new files correctly", 2020-05-27)
had previously changed `add -p` to handle new files but it did not
implement patch editing correctly. The perl version simply forbade
editing and the C version opened the editor with the full diff rather
that just the hunk which meant that the user had to edit the hunk
header manually to get it to work.

The root cause of the problem is that added files store the diff header
with the hunk data rather than separating the two as we do for other
changes. Changing added files to store the diff header separately
fixes the editing problem at the expense of having to special case
empty additions as they no longer have any hunks associated with them,
only the diff header.

The changes move some existing code into a conditional changing the
indentation, they are best viewed with
--color-moved-ws=allow-indentation-change (or --ignore-space-change
works well to get an overview of the changes)

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reported-by: Thomas Sullivan <tom@msbit.com.au>
Reported-by: Yuchen Ying <ych@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-09 12:49:01 -07:00
Phillip Wood 324efcf6b6 add -p: fix memory leak
asan reports that the C version of `add -p` is not freeing all the
memory it allocates. Fix this by introducing a function to clear
`struct add_p_state` and use it instead of freeing individual members.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-08 14:51:38 -07:00
Jeff King dc62641572 add-patch: fix inverted return code of repo_read_index()
After applying hunks to a file with "add -p", the C patch_update_file()
function tries to refresh the index (just like the perl version does).
We can only refresh the index if we're able to read it in, so we first
check the return value of repo_read_index(). But unlike many functions,
where "0" is success, that function is documented to return the number
of entries in the index.  Hence we should be checking for success with a
non-negative return value.

Neither the tests nor any users seem to have noticed this, probably due
to a combination of:

  - this affects only the C version, which is not yet the default

  - following it up with any porcelain command like "git diff" or "git
    commit" would refresh the index automatically.

But you can see the problem by running the plumbing "git diff-files"
immediately after "add -p" stages all hunks. Running the new test with
GIT_TEST_ADD_I_USE_BUILTIN=1 fails without the matching code change.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-08 14:48:29 -07:00
Junio C Hamano cce5178c30 Merge branch 'pw/add-p-allowed-options-fix'
"git add -p" update.

* pw/add-p-allowed-options-fix:
  add -p: fix checking of user input
  add -p: use ALLOC_GROW_BY instead of ALLOW_GROW
2020-09-03 12:37:02 -07:00
Phillip Wood ce910287e7 add -p: fix checking of user input
When a file has been deleted the C version of add -p allows the user
to edit a hunk even though 'e' is not in the list of allowed
responses. (I think 'e' is disallowed because if the file is edited it
is no longer a deletion and we're not set up to rewrite the diff
header).

The invalid response was allowed because the test that determines
whether to display 'e' was not duplicated correctly in the code that
processes the user's choice. Fix this by using flags that are set when
constructing the prompt and checked when processing the user's choice
rather than repeating the check itself.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 11:44:42 -07:00
Phillip Wood 2ebe436c55 add -p: use ALLOC_GROW_BY instead of ALLOW_GROW
This simplifies the code slightly, especially the third case where
hunk_nr was incremented a few lines before ALLOC_GROW().

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-17 11:41:50 -07:00
Junio C Hamano 46b225f153 Merge branch 'jk/strvec'
The argv_array API is useful for not just managing argv but any
"vector" (NULL-terminated array) of strings, and has seen adoption
to a certain degree.  It has been renamed to "strvec" to reduce the
barrier to adoption.

* jk/strvec:
  strvec: rename struct fields
  strvec: drop argv_array compatibility layer
  strvec: update documention to avoid argv_array
  strvec: fix indentation in renamed calls
  strvec: convert remaining callers away from argv_array name
  strvec: convert more callers away from argv_array name
  strvec: convert builtin/ callers away from argv_array name
  quote: rename sq_dequote_to_argv_array to mention strvec
  strvec: rename files from argv-array to strvec
  argv-array: rename to strvec
  argv-array: use size_t for count and alloc
2020-08-10 10:23:57 -07:00
Jeff King d70a9eb611 strvec: rename struct fields
The "argc" and "argv" names made sense when the struct was argv_array,
but now they're just confusing. Let's rename them to "nr" (which we use
for counts elsewhere) and "v" (which is rather terse, but reads well
when combined with typical variable names like "args.v").

Note that we have to update all of the callers immediately. Playing
tricks with the preprocessor is hard here, because we wouldn't want to
rewrite unrelated tokens.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-30 19:18:06 -07:00
Steve Kemp 84544f2ea3 comment: fix spelling mistakes inside comments
This commit fixes a couple of minor spelling mistakes inside
comments.

Signed-off-by: Steve Kemp <steve@steve.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-29 11:39:40 -07:00
Jeff King f6d8942b1f strvec: fix indentation in renamed calls
Code which split an argv_array call across multiple lines, like:

  argv_array_pushl(&args, "one argument",
                   "another argument", "and more",
		   NULL);

was recently mechanically renamed to use strvec, which results in
mis-matched indentation like:

  strvec_pushl(&args, "one argument",
                   "another argument", "and more",
		   NULL);

Let's fix these up to align the arguments with the opening paren. I did
this manually by sifting through the results of:

  git jump grep 'strvec_.*,$'

and liberally applying my editor's auto-format. Most of the changes are
of the form shown above, though I also normalized a few that had
originally used a single-tab indentation (rather than our usual style of
aligning with the open paren). I also rewrapped a couple of obvious
cases (e.g., where previously too-long lines became short enough to fit
on one), but I wasn't aggressive about it. In cases broken to three or
more lines, the grouping of arguments is sometimes meaningful, and it
wasn't worth my time or reviewer time to ponder each case individually.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King ef8d7ac42a strvec: convert more callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King dbbcd44fb4 strvec: rename files from argv-array to strvec
This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe 's/argv-array.h/strvec.h/'

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:17 -07:00
Junio C Hamano 2bdf00e66a Merge branch 'js/checkout-p-new-file'
"git checkout -p" did not handle a newly added path at all.

* js/checkout-p-new-file:
  checkout -p: handle new files correctly
2020-06-08 18:06:31 -07:00
Johannes Schindelin 2c8bd8471a checkout -p: handle new files correctly
The original patch selection code was written for `git add -p`, and the
fundamental unit on which it works is a hunk.

We hacked around that to handle deletions back in 24ab81ae4d
(add-interactive: handle deletion of empty files, 2009-10-27). But `git
add -p` would never see a new file, since we only consider the set of
tracked files in the index.

However, since the same machinery was used for `git checkout -p` &
friends, we can see new files.

Handle this case specifically, adding a new prompt for it that is
modeled after the `deleted file` case.

This also fixes the problem where added _empty_ files could not be
staged via `git checkout -p`.

Reported-by: Merlin Büge <toni@bluenox07.de>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-27 14:50:20 -07:00
Johannes Schindelin 08d383f23e interactive: refactor code asking the user for interactive input
There are quite a few code locations (e.g. `git clean --interactive`)
where Git asks the user for an answer. In preparation for fixing a bug
shared by all of them, and also to DRY up the code, let's refactor it.

Please note that most of these callers trimmed white-space both at the
beginning and at the end of the answer, instead of trimming only the
end (as the caller in `add-patch.c` does).

Therefore, technically speaking, we change behavior in this patch. At
the same time, it can be argued that this is actually a bug fix.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 10:26:31 -07:00
Johannes Schindelin 04f816b125 built-in add -p: respect the `interactive.singlekey` config setting
The Perl version of `git add -p` supports this config setting to allow
users to input commands via single characters (as opposed to having to
press the <Enter> key afterwards).

This is an opt-in feature because it requires Perl packages
(Term::ReadKey and Term::Cap, where it tries to handle an absence of the
latter package gracefully) to work. Note that at least on Ubuntu, that
Perl package is not installed by default (it needs to be installed via
`sudo apt-get install libterm-readkey-perl`), so this feature is
probably not used a whole lot.

In C, we obviously do not have these packages available, but we just
introduced `read_single_keystroke()` that is similar to what
Term::ReadKey provides, and we use that here.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin 08b1ea4c39 built-in add -p: handle diff.algorithm
The Perl version of `git add -p` reads the config setting
`diff.algorithm` and if set, uses it to generate the diff using the
specified algorithm.

This patch ports that functionality to the C version.

Note: just like `git-add--interactive.perl`, we do _not_ respect this
config setting in `git add -i`'s `diff` command, but _only_ in the
`patch` command.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:16 -08:00
Johannes Schindelin 180f48df69 built-in add -p: support interactive.diffFilter
The Perl version supports post-processing the colored diff (that is
generated in addition to the uncolored diff, intended to offer a
prettier user experience) by a command configured via that config
setting, and now the built-in version does that, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:16 -08:00
Johannes Schindelin cee6cb7300 built-in add -p: implement the "worktree" patch modes
This is a straight-forward port of 2f0896ec3a (restore: support
--patch, 2019-04-25) which added support for `git restore -p`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21 16:06:22 -08:00
Johannes Schindelin 52628f94fc built-in add -p: implement the "checkout" patch modes
This patch teaches the built-in `git add -p` machinery all the tricks it
needs to know in order to act as the work horse for `git checkout -p`.

Apart from the minor changes (slightly reworded messages, different
`diff` and `apply --check` invocations), it requires a new function to
actually apply the changes, as `git checkout -p` is a bit special in
that respect: when the desired changes do not apply to the index, but
apply to the work tree, Git does not fail straight away, but asks the
user whether to apply the changes to the worktree at least.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21 16:06:22 -08:00
Johannes Schindelin 36bae1dc0e built-in add -p: implement the "stash" and "reset" patch modes
The `git stash` and `git reset` commands support a `--patch` option, and
both simply hand off to `git add -p` to perform that work. Let's teach
the built-in version of that command to be able to perform that work, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21 16:06:21 -08:00
Johannes Schindelin d2a233cb8b built-in add -p: prepare for patch modes other than "stage"
The Perl script backing `git add -p` is used not only for that command,
but also for `git stash -p`, `git reset -p` and `git checkout -p`.

In preparation for teaching the C version of `git add -p` to support
also the latter commands, let's abstract away what is "stage" specific
into a dedicated data structure describing the differences between the
patch modes.

Finally, please note that the Perl version tries to make sure that the
diffs are only generated for the modified files. This is not actually
necessary, as the calls to Git's diff machinery already perform that
work, and perform it well. This makes it unnecessary to port the
`FILTER` field of the `%patch_modes` struct, as well as the
`get_diff_reference()` function.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21 16:06:21 -08:00
Johannes Schindelin 2e4083198d built-in add -p: show helpful hint when nothing can be staged
This patch will make `git add -p` show "No changes." or "Only binary
files changed." in that case.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 54d9d9b2ee built-in add -p: only show the applicable parts of the help text
When displaying the only hunk in a file's diff, the prompt already
excludes the commands to navigate to the previous/next hunk.

Let's also let the `?` command show only the help lines corresponding to
the commands that are displayed in the prompt.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin ade246efed built-in add -p: implement the 'q' ("quit") command
This command is actually very similar to the 'd' ("do not stage this
hunk or any of the later hunks in the file") command: it just does
something on top, namely leave the loop and return a value indicating
that we're quittin'.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin d6cf873340 built-in add -p: implement the '/' ("search regex") command
This patch implements the hunk searching feature in the C version of
`git add -p`.

A test is added to verify that this behavior matches the one of the Perl
version of `git add -p`.

Note that this involves a change of behavior: the Perl version uses (of
course) the Perl flavor of regular expressions, while this patch uses
the regcomp()/regexec(), i.e. POSIX extended regular expressions. In
practice, this behavior change is unlikely to matter.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 9254bdfb4f built-in add -p: implement the 'g' ("goto") command
With this patch, it is now possible to see a summary of the available
hunks and to navigate between them (by number).

A test is added to verify that this behavior matches the one of the Perl
version of `git add -p`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin bcdd297b78 built-in add -p: implement hunk editing
Just like `git add --edit` allows the user to edit the diff before it is
being applied to the index, this feature allows the user to edit the
diff *hunk*.

Naturally, it gets a bit more complicated here because the result has
to play well with the remaining hunks of the overall diff. Therefore,
we have to do a loop in which we let the user edit the hunk, then test
whether the result would work, and if not, drop the edits and let the
user decide whether to try editing the hunk again.

Note: in contrast to the Perl version, we use the same diff
"coalescing" (i.e. merging overlapping hunks into a single one) also for
the check after editing, and we introduce a new flag for that purpose
that asks the `reassemble_patch()` function to pretend that all hunks
were selected for use.

This allows us to continue to run `git apply` *without* the
`--allow-overlap` option (unlike the Perl version), and it also fixes
two known breakages in `t3701-add-interactive.sh` (which we cannot mark
as resolved so far because the Perl script version is still the default
and continues to have those breakages).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 11f2c0dae8 built-in add -p: coalesce hunks after splitting them
This is considered "the right thing to do", according to 933e44d3a0
("add -p": work-around an old laziness that does not coalesce hunks,
2011-04-06).

Note: we cannot simply modify the hunks while merging them; Once we
implement hunk editing, we will call `reassemble_patch()` whenever a
hunk is edited, therefore we must not modify the hunks (because the user
might e.g. hit `K` and change their mind whether to stage the previous
hunk).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 510aeca199 built-in add -p: implement the hunk splitting feature
If this developer's workflow is any indication, then this is *the* most
useful feature of Git's interactive `add `command.

Note: once again, this is not a verbatim conversion from the Perl code
to C: the `hunk_splittable()` function, for example, essentially did all
the work of splitting the hunk, just to find out whether more than one
hunk would have been the result (and then tossed that result into the
trash). In C we instead count the number of resulting hunks (without
actually doing the work of splitting, but just counting the transitions
from non-context lines to context lines), and store that information
with the hunk, and we do that *while* parsing the diff in the first
place.

Another deviation: the built-in `git add -p` was designed with a single
strbuf holding the diff (and another one holding the colored diff, if
that one was asked for) in mind, and hunks essentially store just the
start and end offsets pointing into that strbuf. As a consequence, when
we split hunks, we now use a special mode where the hunk header is
generated dynamically, and only the rest of the hunk is stored using
such start/end offsets. This way, we also avoid the frequent
formatting/re-parsing of the hunk header of the Perl version.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 0ecd9d27fc built-in add -p: show different prompts for mode changes and deletions
Just like the Perl version, we now helpfully ask the user whether they
want to stage a mode change, or a deletion.

Note that we define the prompts in an array, in preparation for a later
patch that changes those prompts to yet different versions for `git
reset -p`, `git stash -p` and `git checkout -p` (which all call the `git
add -p` machinery to do the actual work).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 5906d5de77 built-in app -p: allow selecting a mode change as a "hunk"
This imitates the way the Perl version treats mode changes: it offers
the mode change up for the user to decide, as if it was a diff hunk.

In contrast to the Perl version, we make use of the fact that the mode
line is the first hunk, and explicitly strip out that line from the diff
header if that "hunk" was not selected to be applied, and skipping that
hunk while coalescing the diff. The Perl version plays some kind of diff
line lego instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:14 -08:00
Johannes Schindelin 47dc4fd5eb built-in add -p: handle deleted empty files
This addresses the same problem as 24ab81ae4d (add-interactive: handle
deletion of empty files, 2009-10-27), although in a different way: we
not only stick the "deleted file" line into its own pseudo hunk, but
also the entire remainder (if any) of the same diff.

That way, we do not have to play any funny games with regards to
coalescing the diff after the user selected what (possibly pseudo-)hunks
to stage.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:13 -08:00
Johannes Schindelin 80399aec5a built-in add -p: support multi-file diffs
For simplicity, the initial implementation in C handled only a single
modified file. Now it handles an arbitrary number of files.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:13 -08:00
Johannes Schindelin 7584dd3c66 built-in add -p: offer a helpful error message when hunk navigation failed
... just like the Perl version currently does...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:13 -08:00
Johannes Schindelin 12c24cf850 built-in add -p: color the prompt and the help text
... just like the Perl version ;-)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:13 -08:00
Johannes Schindelin 25ea47af49 built-in add -p: adjust hunk headers as needed
When skipping a hunk that adds a different number of lines than it
removes, we need to adjust the subsequent hunk headers of non-skipped
hunks: in pathological cases, the context is not enough to determine
precisely where the patch should be applied.

This problem was identified in 23fea4c240 (t3701: add failing test for
pathological context lines, 2018-03-01) and fixed in the Perl version in
fecc6f3a68 (add -p: adjust offsets of subsequent hunks when one is
skipped, 2018-03-01).

And this patch fixes it in the C version of `git add -p`.

In contrast to the Perl version, we try to keep the extra text on the
hunk header (which typically contains the signature of the function
whose code is changed in the hunk) intact.

Note: while the C version does not support staging mode changes at this
stage, we already prepare for this by simply skipping the hunk header if
both old and new offset is 0 (this cannot happen for regular hunks, and
we will use this as an indicator that we are looking at a special hunk).

Likewise, we already prepare for hunk splitting by handling the absence
of extra text in the hunk header gracefully: only the first split hunk
will have that text, the others will not (indicated by an empty extra
text start/end range). Preparing for hunk splitting already at this
stage avoids an indentation change of the entire hunk header-printing
block later, and is almost as easy to review as without that handling.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:37:13 -08:00