git/Documentation/diff-options.txt, branch v2.35.2

Merge branch 'jn/log-m-does-not-imply-p'

2021-08-11T19:36:18Z

Earlier "git log -m" was changed to always produce patch output, which would break existing scripts, which has been reverted. * jn/log-m-does-not-imply-p: Revert 'diff-merges: let "-m" imply "-p"'

Revert 'diff-merges: let "-m" imply "-p"'

2021-08-09T20:52:01Z

This reverts commit f5bfcc823ba242a46e20fb6f71c9fbf7ebb222fe, which made "git log -m" imply "--patch" by default. The logic was that "-m", which makes diff generation for merges perform a diff against each parent, has no use unless I am viewing the diff, so we could save the user some typing by turning on display of the resulting diff automatically. That wasn't expected to adversely affect scripts because scripts would either be using a command like "git diff-tree" that already emits diffs by default or would be combining -m with a diff generation option such as --name-status. By saving typing for interactive use without adversely affecting scripts in the wild, it would be a pure improvement. The problem is that although diff generation options are only relevant for the displayed diff, a script author can imagine them affecting path limiting. For example, I might run git log -w --format=%H -- README hoping to list commits that edited README, excluding whitespace-only changes. In fact, a whitespace-only change is not TREESAME so the use of -w here has no effect (since we don't apply these diff generation flags to the diff_options struct rev_info::pruning used for this purpose), but the documentation suggests that it should work Suppose you specified foo as the . We shall call commits that modify foo !TREESAME, and the rest TREESAME. (In a diff filtered for foo, they look different and equal, respectively.) and a script author who has not tested whitespace-only changes wouldn't notice. Similarly, a script author could include git log -m --first-parent --format=%H -- README to filter the first-parent history for commits that modified README. The -m is a no-op but it reflects the script author's intent. For example, until 1e20a407fe2 (stash list: stop passing "-m" to "git log", 2021-05-21), "git stash list" did this. As a result, we can't safely change "-m" to imply "-p" without fear of breaking such scripts. Restore the previous behavior. Noticed because Rust's src/bootstrap/bootstrap.py made use of this same construct: https://github.com/rust-lang/rust/pull/87513. That script has been updated to omit the unnecessary "-m" option, but we can expect other scripts in the wild to have similar expectations. Signed-off-by: Jonathan Nieder Signed-off-by: Junio C Hamano

diffcore-rename: treat a rename_limit of 0 as unlimited

2021-07-15T23:54:24Z

In commit 89973554b52c (diffcore-rename: make diff-tree -l0 mean -l, 2017-11-29), -l0 was given a special magical "large" value, but one which was not large enough for some uses (as can be seen from commit 9f7e4bfa3b6d (diff: remove silent clamp of renameLimit, 2017-11-13). Make 0 (or a negative value) be treated as unlimited instead and update the documentation to mention this. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

doc: clarify documentation for rename/copy limits

2021-07-15T23:54:24Z

A few places in the docs implied that rename/copy detection is always quadratic or that all (unpaired) files were involved in the quadratic portion of rename/copy detection. The following two commits each introduced an exception to this: 9027f53cb505 (Do linear-time/space rename logic for exact renames, 2007-10-25) bd24aa2f97a0 (diffcore-rename: guide inexact rename detection based on basenames, 2021-02-14) (As a side note, for copy detection, the basename guided inexact rename detection is turned off and the exact renames will only result in sources (without the dests) being removed from the set of files used in quadratic detection. So, for copy detection, the documentation was closer to correct.) Avoid implying that all files involved in rename/copy detection are subject to the full quadratic algorithm. While at it, also note the default values for all these settings. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

Merge branch 'so/log-m-implies-p'

2021-06-14T04:33:27Z

The "-m" option in "git log -m" that does not specify which format, if any, of diff is desired did not have any visible effect; it now implies some form of diff (by default "--patch") is produced. * so/log-m-implies-p: diff-merges: let "-m" imply "-p" diff-merges: rename "combined_imply_patch" to "merges_imply_patch" stash list: stop passing "-m" to "git log" git-svn: stop passing "-m" to "git rev-list" diff-merges: move specific diff-index "-m" handling to diff-index t4013: test "git diff-index -m" t4013: test "git diff-tree -m" t4013: test "git log -m --stat" t4013: test "git log -m --raw" t4013: test that "-m" alone has no effect in "git log"

diff-merges: let "-m" imply "-p"

2021-05-21T00:24:14Z

Fix long standing inconsistency between -c/--cc that do imply -p on one side, and -m that did not imply -p on the other side. Change corresponding test accordingly, as "log -m" output should now match one from "log -m -p", rather than from just "log". Change documentation accordingly. NOTES: After this patch git log -m produces diffs without need to provide -p as well, that improves both consistency and usability. It gets even more useful if one sets "log.diffMerges" configuration variable to "first-parent" to force -m produce usual diff with respect to first parent only. This patch, however, does not change behavior when specific diff format is explicitly provided on the command-line, so that commands like git log -m --raw git log -m --stat are not affected, nor does it change commands where specific diff format is active by default, such as: git diff-tree -m It's also worth to be noticed that exact historical semantics of -m is still provided by --diff-merges=separate. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

Merge branch 'ab/pathname-encoding-doc'

2021-04-30T04:50:27Z

Clarify that pathnames recorded in Git trees are most often (but not necessarily) encoded in UTF-8. * ab/pathname-encoding-doc: doc: clarify the filename encoding in git diff

doc: clarify the filename encoding in git diff

2021-04-20T19:57:26Z

AFAICT parsing the output of `git diff --name-only master...feature` is the intended way of programmatically getting the list of files modified by a feature branch. It is impossible to parse text unless you know what encoding it is in. The output encoding of diff --name-only and Signed-off-by: Junio C Hamano

doc/diff-options: document new --diff-merges features

2021-04-17T06:38:35Z

Document changes in -m and --diff-merges=m semantics, as well as new --diff-merges=on option. Signed-off-by: Sergey Organov Signed-off-by: Junio C Hamano

diff: --{rotate,skip}-to=

2021-02-16T17:30:42Z

In the implementation of "git difftool", there is a case where the user wants to start viewing the diffs at a specific path and continue on to the rest, optionally wrapping around to the beginning. Since it is somewhat cumbersome to implement such a feature as a post-processing step of "git diff" output, let's support it internally with two new options. - "git diff --rotate-to=C", when the resulting patch would show paths A B C D E without the option, would "rotate" the paths to shows patch to C D E A B instead. It is an error when there is no patch for C is shown. - "git diff --skip-to=C" would instead "skip" the paths before C, and shows patch to C D E. Again, it is an error when there is no patch for C is shown. - "git log [-p]" also accepts these two options, but it is not an error if there is no change to the specified path. Instead, the set of output paths are rotated or skipped to the specified path or the first path that sorts after the specified path. Signed-off-by: Junio C Hamano