Re: [PATCH v2 7/7] blame: actually use the diff opts parsed from the command line

[Michael Haggerty <mhagger@alum.mit.edu>]

On 08/23/2016 11:56 AM, René Scharfe wrote:
> Am 22.08.2016 um 13:22 schrieb Michael Haggerty:
>> "git blame" already parsed generic diff options from the command line
>> via diff_opt_parse(), but instead of passing the resulting xdl_opts to
>> xdi_diff(), it sent its own xdl_opts, which only reflected the values of
>> the self-parsed options "-w" and "--minimal". Instead, rely on
>> diff_opt_parse() to parse all of the diff options, including "-w" and
>> "--minimal", and pass the resulting xdl_opts to xdi_diff().
> 
> Sounds useful: It allows more fine-grained control over which whitespace
> changes to ignore and which diff algorithm to use.  There is a bit of
> overlap (e.g. with -b meaning show blank boundaries vs. ignore
> whitespace changes), but with your patch blame's own options still take
> precedence, so there should be no unpleasant surprises.
> 
>> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
>> ---
>> Somebody who knows more about how diff operations are configured
>> should please review this. I'm not certain that the change as
>> implemented won't have other unwanted side-effects, though of course
>> I checked that the test suite runs correctly.
> 
> I don't qualify, but I'll comment anyway..
> 
>>  builtin/blame.c        |  11 ++--
>>  t/t4059-diff-indent.sh | 160
>> +++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 165 insertions(+), 6 deletions(-)
>>  create mode 100755 t/t4059-diff-indent.sh
> 
> This new test doesn't call git blame.  Does it belong to a different
> commit?  And shouldn't the change to blame.c stand on its own, outside
> of this series?

Thanks for catching this. I squashed the test incorrectly; it was meant
to be part of the previous commit. I'll fix it in v3.

The reason that I would prefer to change `blame` as part of this patch
series is that I think it would be disconcerting for `git diff` and `git
blame` to use different heuristics when computing diffs. It would make
their output inconsistent.

But probably that means passing just the new option to `git blame`
rather than passing all possible `diff` options through.

> [...]

Your other comments may be moot given that changing `git blame` in this
way seems to have been a bad idea in the first place [1]. But I'll keep
them in mind if a new version contains similar code.

Thanks,
Michael

[1]
http://public-inbox.org/git/xmqqtwebwhbg.fsf@gitster.mtv.corp.google.com/