git/Documentation/config/diff.txt, branch v2.45.2

diff.*Prefix: use camelCase in the doc and test titles

2024-03-18T15:47:18Z

We added documentation for diff.srcPrefix and diff.dstPrefix with their names properly camelCased, but the diff.noPrefix is listed there in all lowercase. Also these configuration variables, both existing ones and the {src,dst}Prefix we recently added, were spelled in all lowercase in the tests in t4013. Now we are done with the main change, clean these up. Signed-off-by: Junio C Hamano Reviewed-by: Peter Hutterer Signed-off-by: Junio C Hamano

diff: add diff.srcPrefix and diff.dstPrefix configuration variables

2024-03-15T17:04:45Z

Allow the default prefixes "a/" and "b/" to be tweaked by the diff.srcPrefix and diff.dstPrefix configuration variables. Signed-off-by: Peter Hutterer Signed-off-by: Junio C Hamano

doc: end sentences with full-stop

2024-02-20T23:03:13Z

Signed-off-by: Jean-Noël Avila Signed-off-by: Junio C Hamano

documentation: fix singular vs. plural

2023-10-09T19:06:29Z

Diff best viewed with --color-diff. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano

diff --stat: add config option to limit filename width

2023-09-18T16:39:07Z

Add new configuration option diff.statNameWidth= that is equivalent to the command-line option --stat-name-width=, but it is ignored by format-patch. This follows the logic established by the already existing configuration option diff.statGraphWidth=. Limiting the widths of names and graphs in the --stat output makes sense for interactive work on wide terminals with many columns, hence the support for these configuration options. They don't affect format-patch because it already adheres to the traditional 80-column standard. Update the documentation and add more tests to cover new configuration option diff.statNameWidth=. While there, perform a few minor code and whitespace cleanups here and there, as spotted. Signed-off-by: Dragan Simic Signed-off-by: Junio C Hamano

difftool docs: de-duplicate configuration sections

2022-09-07T16:46:06Z

Include the "config/difftool.txt" file in "git-difftool.txt", and move the relevant part of git-difftool(1) configuration from "config/diff.txt" to config/difftool.txt". Doing this is slightly odd, as we usually discuss configuration in alphabetical order, but by doing it we're able to include the full set of configuration used by git-difftool(1) (and only that configuration) in its own documentation. Signed-off-by: Ævar Arnfjörð Bjarmason Reviewed-by: Matheus Tavares Signed-off-by: Junio C Hamano

rename: bump limit defaults yet again

2021-07-15T23:54:34Z

These were last bumped in commit 92c57e5c1d29 (bump rename limit defaults (again), 2011-02-19), and were bumped both because processors had gotten faster, and because people were getting ugly merges that caused problems and reporting it to the mailing list (suggesting that folks were willing to spend more time waiting). Since that time: * Linus has continued recommending kernel folks to set diff.renameLimit=0 (maps to 32767, currently) * Folks with repositories with lots of renames were happy to set merge.renameLimit above 32767, once the code supported that, to get correct cherry-picks * Processors have gotten faster * It has been discovered that the timing methodology used last time probably used too large example files. The last point is probably worth explaining a bit more: * The "average" file size used appears to have been average blob size in the linux kernel history at the time (probably v2.6.25 or something close to it). * Since bigger files are modified more frequently, such a computation weights towards larger files. * Larger files may be more likely to be modified over time, but are not more likely to be renamed -- the mean and median blob size within a tree are a bit higher than the mean and median of blob sizes in the history leading up to that version for the linux kernel. * The mean blob size in v2.6.25 was half the average blob size in history leading to that point * The median blob size in v2.6.25 was about 40% of the mean blob size in v2.6.25. * Since the mean blob size is more than double the median blob size, any file as big as the mean will not be compared to any files of median size or less (because they'd be more than 50% dissimilar). * Since it is the number of files compared that provides the O(n^2) behavior, median-sized files should matter more than mean-sized ones. The combined effect of the above is that the file size used in past calculations was likely about 5x too large. Combine that with a CPU performance improvement of ~30%, and we can increase the limits by a factor of sqrt(5/(1-.3)) = 2.67, while keeping the original stated time limits. Keeping the same approximate time limit probably makes sense for diff.renameLimit (there is no progress feedback in e.g. git log -p), but the experience above suggests merge.renameLimit could be extended significantly. In fact, it probably would make sense to have an unlimited default setting for merge.renameLimit, but that would likely need to be coupled with changes to how progress is displayed. (See https://lore.kernel.org/git/YOx+Ok%2FEYvLqRMzJ@coredump.intra.peff.net/ for details in that area.) For now, let's just bump the approximate time limit from 10s to 1m. (Note: We do not want to use actual time limits, because getting results that depend on how loaded your system is that day feels bad, and because we don't discover that we won't get all the renames until after we've put in a lot of work rather than just upfront telling the user there are too many files involved.) Using the original time limit of 2s for diff.renameLimit, and bumping merge.renameLimit from 10s to 60s, I found the following timings using the simple script at the end of this commit message (on an AWS c5.xlarge which reports as "Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz"): N Timing 1300 1.995s 7100 59.973s So let's round down to nice even numbers and bump the limits from 400->1000, and from 1000->7000. Here is the measure_rename_perf script (adapted from https://lore.kernel.org/git/20080211113516.GB6344@coredump.intra.peff.net/ in particular to avoid triggering the linear handling from basename-guided rename detection): #!/bin/bash n=$1; shift rm -rf repo mkdir repo && cd repo git init -q -b main mkdata() { mkdir $1 for i in `seq 1 $2`; do (sed "s/^/$i /" <../sample echo tag: $1 ) >$1/$i done } mkdata initial $n git add . git commit -q -m initial mkdata new $n git add . cd new for i in *; do git mv $i $i.renamed; done cd .. git rm -q -rf initial git commit -q -m new time git diff-tree -M -l0 --summary HEAD^ HEAD 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

diff: do not show submodule with untracked files as "-dirty"

2020-12-08T22:27:35Z

Git diff reports a submodule directory as -dirty even when there are only untracked files in the submodule directory. This is inconsistent with what `git describe --dirty` says when run in the submodule directory in that state. Make `--ignore-submodules=untracked` the default for `git diff` when there is no configuration variable or command line option, so that the command would not give '-dirty' suffix to a submodule whose working tree has untracked files, to make it consistent with `git describe --dirty` that is run in the submodule working tree. And also make `--ignore-submodules=none` the default for `git status` so that the user doesn't end up deleting a submodule that has uncommitted (untracked) files. Signed-off-by: Sangeeta Jain Signed-off-by: Junio C Hamano

diff: add config option relative

2020-05-24T23:23:59Z

The `diff.relative` boolean option set to `true` shows only changes in the current directory/value specified by the `path` argument of the `relative` option and shows pathnames relative to the aforementioned directory. Teach `--no-relative` to override earlier `--relative` Add for git-format-patch(1) options documentation `--relative` and `--no-relative` Signed-off-by: Laurent Arnoud Acked-by: Đoàn Trần Công Danh Signed-off-by: Junio C Hamano