From ffffb987fcd3b3d6b88aceed87000ef4a5b6114e Mon Sep 17 00:00:00 2001 From: Antonin Delpeuch Date: Mon, 17 Nov 2025 08:04:32 +0000 Subject: blame: make diff algorithm configurable The diff algorithm used in 'git-blame(1)' is set to 'myers', without the possibility to change it aside from the `--minimal` option. There has been long-standing interest in changing the default diff algorithm to "histogram", and Git 3.0 was floated as a possible occasion for taking some steps towards that: https://lore.kernel.org/git/xmqqed873vgn.fsf@gitster.g/ As a preparation for this move, it is worth making sure that the diff algorithm is configurable where useful. Make it configurable in the `git-blame(1)` command by introducing the `--diff-algorithm` option and make honor the `diff.algorithm` config variable. Keep Myers diff as the default. Signed-off-by: Antonin Delpeuch Signed-off-by: Junio C Hamano --- Documentation/diff-algorithm-option.adoc | 20 ++++++++++++++++++++ Documentation/diff-options.adoc | 21 +-------------------- Documentation/git-blame.adoc | 2 ++ 3 files changed, 23 insertions(+), 20 deletions(-) create mode 100644 Documentation/diff-algorithm-option.adoc (limited to 'Documentation') diff --git a/Documentation/diff-algorithm-option.adoc b/Documentation/diff-algorithm-option.adoc new file mode 100644 index 0000000000..8e3a0b63d7 --- /dev/null +++ b/Documentation/diff-algorithm-option.adoc @@ -0,0 +1,20 @@ +`--diff-algorithm=(patience|minimal|histogram|myers)`:: + Choose a diff algorithm. The variants are as follows: ++ +-- + `default`;; + `myers`;; + The basic greedy diff algorithm. Currently, this is the default. + `minimal`;; + Spend extra time to make sure the smallest possible diff is + produced. + `patience`;; + Use "patience diff" algorithm when generating patches. + `histogram`;; + This algorithm extends the patience algorithm to "support + low-occurrence common elements". +-- ++ +For instance, if you configured the `diff.algorithm` variable to a +non-default value and want to use the default one, then you +have to use `--diff-algorithm=default` option. diff --git a/Documentation/diff-options.adoc b/Documentation/diff-options.adoc index ae31520f7f..9cdad6f72a 100644 --- a/Documentation/diff-options.adoc +++ b/Documentation/diff-options.adoc @@ -197,26 +197,7 @@ and starts with __, this algorithm attempts to prevent it from appearing as a deletion or addition in the output. It uses the "patience diff" algorithm internally. -`--diff-algorithm=(patience|minimal|histogram|myers)`:: - Choose a diff algorithm. The variants are as follows: -+ --- - `default`;; - `myers`;; - The basic greedy diff algorithm. Currently, this is the default. - `minimal`;; - Spend extra time to make sure the smallest possible diff is - produced. - `patience`;; - Use "patience diff" algorithm when generating patches. - `histogram`;; - This algorithm extends the patience algorithm to "support - low-occurrence common elements". --- -+ -For instance, if you configured the `diff.algorithm` variable to a -non-default value and want to use the default one, then you -have to use `--diff-algorithm=default` option. +include::diff-algorithm-option.adoc[] `--stat[=[,[,]]]`:: Generate a diffstat. By default, as much space as necessary diff --git a/Documentation/git-blame.adoc b/Documentation/git-blame.adoc index e438d28625..adcbb6f5dc 100644 --- a/Documentation/git-blame.adoc +++ b/Documentation/git-blame.adoc @@ -85,6 +85,8 @@ include::blame-options.adoc[] Ignore whitespace when comparing the parent's version and the child's to find where the lines came from. +include::diff-algorithm-option.adoc[] + --abbrev=:: Instead of using the default 7+1 hexadecimal digits as the abbreviated object name, use +1 digits, where is at -- cgit v1.3