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>
This commit is contained in:
Junio C Hamano 2024-05-06 09:40:31 -07:00
parent 786a3e4b8d
commit c22d41d641
3 changed files with 12 additions and 1 deletions

View file

@ -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::

View file

@ -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");

View file

@ -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;