format-patch: run range-diff with larger creation-factor

We see too often that a range-diff added to format-patch output shows too many "unmatched" patches. This is because the default value for creation-factor is set to a relatively low value. It may be justified for other uses (like you have a yet-to-be-sent new iteration of your series, and compare it against the 'seen' branch that has an older iteration, probably with the '--left-only' option, to pick out only your patches while ignoring the others) of "range-diff" command, but when the command is run as part of the format-patch, the user _knows_ and expects that the patches in the old and the new iterations roughly correspond to each other, so we can and should use a much higher default. Signed-off-by: Junio C Hamano <gitster@pobox.com>

Junio C Hamano committed May 6, 2024 at 09:40 UTC c22d41d641711879c57299244ae13b6c4a215fee
3 files changed +12 -1
Documentation/git-format-patch.txt
+5
index 728bb3821c..b72f87b114 100644 --- a/Documentation/git-format-patch.txt +++ b/Documentation/git-format-patch.txt @@ -346,6 +346,11 @@ material (this may change in the future). between the previous and current series of patches by adjusting the creation/deletion cost fudge factor. See linkgit:git-range-diff[1]) for details. ++ +Defaults to 999 (the linkgit:git-range-diff[1] uses 60), as the use +case is to show comparison with an older iteration of the same +topic and the tool should find more correspondence between the two +sets of patches. --notes[=<ref>]:: --no-notes::
builtin/log.c
+1 -1
index c0a8bb95e9..73608ffef9 100644 --- a/builtin/log.c +++ b/builtin/log.c @@ -2274,7 +2274,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix) } if (creation_factor < 0) - creation_factor = RANGE_DIFF_CREATION_FACTOR_DEFAULT; + creation_factor = CREATION_FACTOR_FOR_THE_SAME_SERIES; else if (!rdiff_prev) die(_("the option '%s' requires '%s'"), "--creation-factor", "--range-diff");
range-diff.h
+6
index 04ffe217be..2f69f6a434 100644 --- a/range-diff.h +++ b/range-diff.h @@ -6,6 +6,12 @@ #define RANGE_DIFF_CREATION_FACTOR_DEFAULT 60 +/* + * A much higher value than the default, when we KNOW we are comparing + * the same series (e.g., used when format-patch calls range-diff). + */ +#define CREATION_FACTOR_FOR_THE_SAME_SERIES 999 + struct range_diff_options { int creation_factor; unsigned dual_color:1;