git/diff.c, branch v2.40.2

Merge branch 'jc/diff-algo-attribute'

2023-02-27T18:08:56Z

The "diff" drivers specified by the "diff" attribute attached to paths can now specify which algorithm (e.g. histogram) to use. * jc/diff-algo-attribute: diff: teach diff to read algorithm from diff driver diff: consolidate diff algorithm option parsing

diff: teach diff to read algorithm from diff driver

2023-02-21T17:29:10Z

It can be useful to specify diff algorithms per file type. For example, one may want to use the minimal diff algorithm for .json files, another for .c files, etc. The diff machinery already checks attributes for a diff driver. Teach the diff driver parser a new type "algorithm" to look for in the config, which will be used if a driver has been specified through the attributes. Enforce precedence of the diff algorithm by favoring the command line option, then looking at the driver attributes & config combination, then finally the diff.algorithm config. To enforce precedence order, use a new `ignore_driver_algorithm` member during options parsing to indicate the diff algorithm was set via command line args. Signed-off-by: John Cai Signed-off-by: Junio C Hamano

diff: consolidate diff algorithm option parsing

2023-02-21T17:29:08Z

A subsequent commit will need the ability to tell if the diff algorithm was set through the command line through setting a new member of diff_options. While this logic can be added to the diff_opt_diff_algorithm() callback, the `--minimal` and `--histogram` options are handled via OPT_BIT without a callback. Remedy this by consolidating the options parsing logic for --minimal and --histogram into one callback. This way we can modify `diff_options` in that function. As an additional refactor, the logic that sets the diff algorithm in diff_opt_diff_algorithm() can be refactored into a helper that will allow multiple callsites to set the diff algorithm. Signed-off-by: John Cai Signed-off-by: Junio C Hamano

Merge branch 'jk/ext-diff-with-relative'

2023-01-16T20:07:46Z

"git diff --relative" did not mix well with "git diff --ext-diff", which has been corrected. * jk/ext-diff-with-relative: diff: drop "name" parameter from prepare_temp_file() diff: clean up external-diff argv setup diff: use filespec path to set up tempfiles for ext-diff

diff: drop "name" parameter from prepare_temp_file()

2023-01-06T12:50:09Z

The prepare_temp_file() function takes a diff_filespec as well as a filename. But it is almost certainly an error to pass in a name that isn't the filespec's "path" parameter, since that is the only thing that reliably tells us how to find the content (and indeed, this was the source of a recently-fixed bug). So let's drop the redundant "name" parameter and just use one->path throughout the function. This simplifies the interface a little bit, and makes it impossible for calling code to get it wrong. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

diff: clean up external-diff argv setup

2023-01-06T12:50:07Z

Since the previous commit, setting up the tempfile for an external diff uses df->path from the diff_filespec, rather than the logical name. This means add_external_diff_name() does not need to take a "name" parameter at all, and we can drop it. And that in turn lets us simplify the conditional for handling renames (when the "other" name is non-NULL). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

diff: use filespec path to set up tempfiles for ext-diff

2023-01-06T12:49:55Z

When we're going to run an external diff, we have to make the contents of the pre- and post-images available either by dumping them to a tempfile, or by pointing at a valid file in the worktree. The logic of this is all handled by prepare_temp_file(), and we just pass in the filename and the diff_filespec. But there's a gotcha here. The "filename" we have is a logical filename and not necessarily a path on disk or in the repository. This matters in at least one case: when using "--relative", we may have a name like "foo", even though the file content is found at "subdir/foo". As a result, we look for the wrong path, fail to find "foo", and claim that the file has been deleted (passing "/dev/null" to the external diff, rather than the correct worktree path). We can fix this by passing the pathname from the diff_filespec, which should always be a full repository path (and that's what we want even if reusing a worktree file, since we're always operating from the top-level of the working tree). The breakage seems to go all the way back to cd676a5136 (diff --relative: output paths as relative to the current subdirectory, 2008-02-12). As far as I can tell, before then "name" would always have been the same as the filespec's "path". There are two related cases I looked at that aren't buggy: 1. the only other caller of prepare_temp_file() is run_textconv(). But it always passes the filespec's path field, so it's OK. 2. I wondered if file renames/copies might cause similar confusion. But they don't, because run_external_diff() receives two names in that case: "name" and "other", which correspond to the two sides of the diff. And we did correctly pass "other" when handling the post-image side. Barring the use of "--relative", that would always match "two->path", the path of the second filespec (and the rename destination). So the only bug is just the interaction with external diff drivers and --relative. Reported-by: Carl Baldwin Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'pg/diff-stat-unmerged-regression-fix'

2022-12-26T02:42:07Z

The output from "git diff --stat" on an unmerged path lost the terminating LF in Git 2.39, which has been corrected. * pg/diff-stat-unmerged-regression-fix: diff: fix regression with --stat and unmerged file

Merge branch 'jk/unused-post-2.39'

2022-12-26T02:42:05Z

Code clean-up around unused function parameters. * jk/unused-post-2.39: userdiff: mark unused parameter in internal callback list-objects-filter: mark unused parameters in virtual functions diff: mark unused parameters in callbacks xdiff: mark unused parameter in xdl_call_hunk_func() xdiff: drop unused parameter in def_ff() ws: drop unused parameter from ws_blank_line() list-objects: drop process_gitlink() function blob: drop unused parts of parse_blob_buffer() ls-refs: use repository parameter to iterate refs

Merge branch 'rs/diff-parseopts'

2022-12-19T02:46:17Z

The way the diff machinery prepares the options array for the parse_options API has been refactored to avoid resource leaks. * rs/diff-parseopts: diff: remove parseopts member from struct diff_options diff: use add_diff_options() in diff_opt_parse() diff: factor out add_diff_options()