git/add-patch.c, branch v2.25.0

built-in add -p: show helpful hint when nothing can be staged

2019-12-13T20:37:14Z

This patch will make `git add -p` show "No changes." or "Only binary files changed." in that case. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano

built-in add -p: only show the applicable parts of the help text

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: implement the 'q' ("quit") command

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: implement the '/' ("search regex") command

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: implement the 'g' ("goto") command

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: implement hunk editing

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: coalesce hunks after splitting them

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: implement the hunk splitting feature

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in add -p: show different prompts for mode changes and deletions

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano

built-in app -p: allow selecting a mode change as a "hunk"

2019-12-13T20:37:14Z

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 Signed-off-by: Junio C Hamano