Re: [PATCH 6/6] fsmonitor: Use fsmonitor data in `git diff`

[Ben Peart <peartben@gmail.com>]

On 1/5/2018 5:22 PM, Junio C Hamano wrote:
> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
>>> diff --git a/diff-lib.c b/diff-lib.c
>>> index 8104603a3..13ff00d81 100644
>>> --- a/diff-lib.c
>>> +++ b/diff-lib.c
>>> @@ -95,6 +95,9 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
>>>   
>>>   	diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
>>>   
>>> +	if (!(option & DIFF_SKIP_FSMONITOR))
>>> +		refresh_fsmonitor(&the_index);
>>> +
>>>   	if (diff_unmerged_stage < 0)
>>>   		diff_unmerged_stage = 2;
>>
>> I read over this hunk five times, and only now am I able to wrap my head
>> around this: if we do *not* want to skip the fsmonitor data, we refresh
>> the fsmonitor data in the index.
>>
>> That feels a bit like an unneeded double negation. Speaking for myself, I
>> would prefore `DIFF_IGNORE_FSMONITOR` instead, it would feel less like a
>> double negation then. But I am not a native speaker, so I might be wrong.
> 
> I do find the logic a bit convoluted with double negative.
> 

It's great to see more use of the fsmonitor data.  Thanks for doing this!

I agree with the sentiment that the logic as written is confusing.  I'll 
also point out that DIFF_IGNORE_FSMONITOR would be more consistent with 
the similar CE_MATCH_IGNORE_FSMONITOR flag and logic.

I'm also confused why we would not want to use the fsmonitor data in the 
'add' case.  When would you ever need to add a file that had not been 
modified?