Subject: Re: [PATCH v6 0/2] blame: make diff algorithm configurable

From: Phillip Wood <[email-masked]>
Date: Mon, 17 Nov 2025 14:13:12 +0000

Hi Antonin

On 17/11/2025 08:04, Antonin Delpeuch via GitGitGadget wrote:
> Changes since v5:
> 
>   * add back /* clear out previous settings */ comments
>   * remove whitespace in bash output redirection

Thanks for re-rolling, the range-diff below looks good. Being able to 
configure the diff algorithm for "git blame" is a nice addition, thanks 
for working on it.

Phillip

> Antonin Delpeuch (2):
>    xdiff: add 'minimal' to XDF_DIFF_ALGORITHM_MASK
>    blame: make diff algorithm configurable
> 
>   Documentation/diff-algorithm-option.adoc |  20 +++
>   Documentation/diff-options.adoc          |  21 +--
>   Documentation/git-blame.adoc             |   2 +
>   builtin/blame.c                          |  52 +++++-
>   diff.c                                   |   1 -
>   merge-ort.c                              |   1 -
>   t/meson.build                            |   1 +
>   t/t8015-blame-diff-algorithm.sh          | 203 +++++++++++++++++++++++
>   xdiff/xdiff.h                            |   2 +-
>   9 files changed, 279 insertions(+), 24 deletions(-)
>   create mode 100644 Documentation/diff-algorithm-option.adoc
>   create mode 100755 t/t8015-blame-diff-algorithm.sh
> 
> 
> base-commit: 4253630c6f07a4bdcc9aa62a50e26a4d466219d1
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2075%2Fwetneb%2Fblame_respects_diff_algorithm-v6
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2075/wetneb/blame_respects_diff_algorithm-v6
> Pull-Request: https://github.com/git/git/pull/2075
> 
> Range-diff vs v5:
> 
>   1:  e81a5d2bd2 ! 1:  4846715436 xdiff: add 'minimal' to XDF_DIFF_ALGORITHM_MASK
>       @@ Commit message
>        
>         ## diff.c ##
>        @@ diff.c: static int set_diff_algorithm(struct diff_options *opts,
>       - 	if (value < 0)
>         		return -1;
>         
>       --	/* clear out previous settings */
>       + 	/* clear out previous settings */
>        -	DIFF_XDL_CLR(opts, NEED_MINIMAL);
>         	opts->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
>         	opts->xdl_opts |= value;
>       @@ diff.c: static int set_diff_algorithm(struct diff_options *opts,
>        
>         ## merge-ort.c ##
>        @@ merge-ort.c: int parse_merge_opt(struct merge_options *opt, const char *s)
>       - 		long value = parse_algorithm_value(arg);
>         		if (value < 0)
>         			return -1;
>       --		/* clear out previous settings */
>       + 		/* clear out previous settings */
>        -		DIFF_XDL_CLR(opt, NEED_MINIMAL);
>         		opt->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
>         		opt->xdl_opts |= value;
>   2:  60015bbada ! 2:  c477b87cc6 blame: make diff algorithm configurable
>       @@ t/t8015-blame-diff-algorithm.sh (new)
>        +	Commit_1 }
>        +	EOF
>        +
>       -+	git blame file.c > output &&
>       -+	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output > without_varying_parts &&
>       -+	sed -e "s/ *$//g" without_varying_parts > actual &&
>       ++	git blame file.c >output &&
>       ++	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output >without_varying_parts &&
>       ++	sed -e "s/ *$//g" without_varying_parts >actual &&
>        +	test_cmp expected actual
>        +'
>        +
>       @@ t/t8015-blame-diff-algorithm.sh (new)
>        +	Commit_2 }
>        +	EOF
>        +
>       -+	git blame file.c --diff-algorithm histogram > output &&
>       -+	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output > without_varying_parts &&
>       -+	sed -e "s/ *$//g" without_varying_parts > actual &&
>       ++	git blame file.c --diff-algorithm histogram >output &&
>       ++	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output >without_varying_parts &&
>       ++	sed -e "s/ *$//g" without_varying_parts >actual &&
>        +	test_cmp expected actual
>        +'
>        +
>       @@ t/t8015-blame-diff-algorithm.sh (new)
>        +	Commit_2 }
>        +	EOF
>        +
>       -+	git -c diff.algorithm=histogram blame file.c > output &&
>       ++	git -c diff.algorithm=histogram blame file.c >output &&
>        +	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" \
>       -+	    -e "s/ *$//g" output > actual &&
>       ++	    -e "s/ *$//g" output >actual &&
>        +	test_cmp expected actual
>        +'
>        +
>       @@ t/t8015-blame-diff-algorithm.sh (new)
>        +	Commit_2 }
>        +	EOF
>        +
>       -+	git -c diff.algorithm=myers blame file.c --diff-algorithm histogram > output &&
>       ++	git -c diff.algorithm=myers blame file.c --diff-algorithm histogram >output &&
>        +	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" \
>       -+	    -e "s/ *$//g" output > actual &&
>       ++	    -e "s/ *$//g" output >actual &&
>        +	test_cmp expected actual
>        +'
>        +
>       @@ t/t8015-blame-diff-algorithm.sh (new)
>        +	Commit_2 G
>        +	EOF
>        +
>       -+	git blame file.txt --minimal > output &&
>       -+	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output > actual &&
>       ++	git blame file.txt --minimal >output &&
>       ++	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output >actual &&
>        +	test_cmp expected actual
>        +'
>        +
>       @@ t/t8015-blame-diff-algorithm.sh (new)
>        +	Commit_2 G
>        +	EOF
>        +
>       -+	git blame file.txt --minimal --diff-algorithm myers > output &&
>       -+	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output > actual &&
>       ++	git blame file.txt --minimal --diff-algorithm myers >output &&
>       ++	sed -e "s/^[^ ]* (\([^ ]*\) [^)]*)/\1/g" output >actual &&
>        +	test_cmp expected actual
>        +'
>        +
>