> Ævar Arnfjörð Bjarmason <ava...@gmail.com> hat am 22. November 2018 um 11:16
> geschrieben:
[...]
> >
> > +test_expect_success 'log -G ignores binary files' '
> > + rm -rf .git &&
> > + git init &&
> > + printf "a\0b" >data.bin &&
> > + git add data.bin &&
> > + git commit -m "message" &&
> > + git log -G a >result &&
>
> Would be less confusing as "-Ga" since that's the invocation we
> document, even though I see (but wasn't aware that...) "-G a" works too.
Done.
> > + test_must_be_empty result
> > +'
> > +
> > +test_expect_success 'log -G looks into binary files with textconv filter' '
> > + rm -rf .git &&
> > + git init &&
> > + echo "* diff=bin" > .gitattributes &&
> > + printf "a\0b" >data.bin &&
> > + git add data.bin &&
> > + git commit -m "message" &&
> > + git -c diff.bin.textconv=cat log -G a >actual &&
> > + git log >expected &&
> > + test_cmp actual expected
> > +'
> > +
> > test_done
>
> This patch seems like the wrong direction to me. In particular the
> assertion that "the concept of differences only makes sense for text
> files". That's just not true. This patch breaks this:
>
> (
> rm -rf /tmp/g-test &&
> git init /tmp/g-test &&
> cd /tmp/g-test &&
> for i in {1..10}; do
> echo "Always matching thensome 5" >file &&
> printf "a thensome %d binary \0" $i >>file &&
> git add file &&
> git commit -m"Bump $i"
> done &&
> git log -Gthensome.*5
> )
>
> Right now this will emit 3/10 patches, and the right ones! I.e. "Bump
> [156]". The 1st one because it introduces the "Always matching thensome
> 5". Then 5/6 because the add/remove the string "a thensome 5 binary",
> respectively. Which matches /thensome.*5/.
log -p does not show you the patch text in your example because it is treated
as binary. And currently "log -G" has a different opinion into what it looks
and what it ignores. My patch tries to bring both more in line.
> I.e. in the first one we do a regex match against the content here
> because we don't have both sides:
> https://github.com/git/git/blob/v2.19.2/diffcore-pickaxe.c#L48-L53
>
> And then for the later ones where we have both sides we end up in
> diffgrep_consume():
> https://github.com/git/git/blob/v2.19.2/diffcore-pickaxe.c#L27-L36
>
> I think there may be a real issue here to address, which might be some
> combination of:
>
> a) Even though the diffcore can do a binary diff internally, this is
> not what it exposes with "-p", we just say "Binary files differ".
>
> I don't know how to emit the raw version we'll end up passing to
> diffgrep_consume() in this case. Is it just --binary without the
> encoding? I don't know...
>
> b) Your test case shows that you're matching a string at a \0
> boundary. Is this perhaps something you ran into? I.e. that we don't
> have some -F version of -G so we can't supply regexes that match
> past a \0? I had some related work on grep for this that hasn't been
> carried over to the diffcore:
>
> git log --grep='grep:.*\\0' --author=Ævar
>
> c) Is this binary diff we end up matching against just bad in some
> cases? I haven't dug but that wouldn't surprise me, i.e. that it's
> trying to be line-based so we'll overmatch in many cases.
>
> So maybe this is something that should be passed down as a flag? See a
> recent discussion at
> https://public-inbox.org/git/87lg77cmr1....@evledraar.gmail.com/ for how
> that could be done.
It is not about the \0 boundary. v2 of the patches will clarify that. My main
motiviation is to speed up "log -G" as that takes a considerable amount of time
when it wades through MBs of binary files which change often. And in multiple
places
I can already treat binary files differently (e.g. turn off delta compression,
skip
trying to diff them, no EOL normalization). And for me making log -G ignore
what git
thinks are binary files is making the line clearer between what should be
treated
as binary and what as text.
> Also if we don't have some tests already that were failing with this
> patch we really should have those as "let's test the current behavior
> first". Unfortunately tests in this area are really lacking, see
> e.g. my:
>
> git log --author=Junio --min-parents=2 --grep=ab/.*grep
>
> For some series of patches to grep where to get one patch in I needed to
> often lead with 5-10 test patches to convince reviewers that I knew what
> I was changing, and also to be comfortable that I'd covered all the edge
> cases we currently supported, but weren't testing for.
I'm happy to add more test cases to convince everyone involved :)
