On Fri, Mar 15 2019, Eric Sunshine wrote: > On Fri, Mar 15, 2019 at 12:09 PM Ævar Arnfjörð Bjarmason > <avarab@xxxxxxxxx> wrote: >> diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt >> @@ -261,6 +261,10 @@ material (this may change in the future). >> +Defaults to 90, whereas the linkgit:git-range-diff[1] default is >> +60. It's assumed that you're submitting a new patch series & that we >> +should try harder than normal to find similarities. > > My understanding was that the primary use-case of git-range-diff > itself (which existed before the --range-diff option was added to > git-format-patch) was to generate a "range diff" for a cover letter of > a re-rolled series. So, I'm confused about why this tweaks the default > value of one command but not the other. > >> diff --git a/range-diff.h b/range-diff.h >> @@ -4,6 +4,7 @@ >> #define RANGE_DIFF_CREATION_FACTOR_DEFAULT 60 >> +#define RANGE_DIFF_CREATION_FACTOR_FORMAT_PATCH_DEFAULT 90 > > The point of introducing RANGE_DIFF_CREATION_FACTOR_DEFAULT in the > first place was to ensure that the default creation-factor didn't get > out-of-sync between git-range-diff and git-format-patch., Thus, > introducing this sort of inconsistency between the two would likely > lead to confusion on the part of users. After all, --range-diff was > added to git-format-patch merely as a convenience over having to run > git-range-diff separately and copy/pasting its output into a cover > letter generated by git-format-patch. If the two programs default to > different values, then that "convenience equality" breaks down. > > So, I'm fairly negative on this change. However, that doesn't mean I > would oppose tweaking the value shared between the two programs (and > also the default used by GitGitGadget, if it specifies it manually), > though I defer to Dscho in that regard. I think that was the intention initially, but at least I'm now using range-diff as a general comparison tool of different non-ff-branches, e.g. the force-pushes to "pu". I'd expect the tool in general to be used like that, whereas with format-patch it's safe to say we're dealing with a re-roll of the same thing. Hence the hypothesis that for format-patch we can be more aggressive about finding similarities.
