Re: [PATCH 3/7] revision: use die_for_incompatible_opt3() for --graph/--reverse/--walk-reflogs

> On Wed, Dec 06, 2023 at 12:51:57PM +0100, René Scharfe wrote:
>> The revision options --reverse is incompatibel with --walk-reflogs and
>> --graph is incompatible with both --reverse and --walk-reflogs.  So they
>> are all incompatible with each other.
>>
>> Use the function for checking three mutually incompatible options,
>> die_for_incompatible_opt3(), to perform this check in one place and
>> without repetition.  This is shorter and clearer.
>>
>> Signed-off-by: René Scharfe <l.s.r@web.de>
>> ---
>>  revision.c | 9 +++------
>>  1 file changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/revision.c b/revision.c
>> index b2861474b1..1b7e1af6c6 100644
>> --- a/revision.c
>> +++ b/revision.c
>> @@ -3036,8 +3036,6 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
>>  		revs->grep_filter.ignore_locale = 1;
>>  	compile_grep_patterns(&revs->grep_filter);
>>
>> -	if (revs->reverse && revs->reflog_info)
>> -		die(_("options '%s' and '%s' cannot be used together"), "--reverse", "--walk-reflogs");
>>  	if (revs->reflog_info && revs->limited)
>>  		die("cannot combine --walk-reflogs with history-limiting options");
>>  	if (revs->rewrite_parents && revs->children.name)
>> @@ -3048,11 +3046,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
>>  	/*
>>  	 * Limitations on the graph functionality
>>  	 */
>> -	if (revs->reverse && revs->graph)
>> -		die(_("options '%s' and '%s' cannot be used together"), "--reverse", "--graph");
>> +	die_for_incompatible_opt3(!!revs->graph, "--graph",
>> +				  !!revs->reverse, "--reverse",
>> +				  !!revs->reflog_info, "--walk-reflogs");
>
> I've been wondering why we use `!!` here, as `die_for_incompatible_*()`
> doesn't care for the actual value but only checks that it is non-zero.
> Is it because of the type mismatch, where these flags here use unsigned
> ints whereas `die_for_incompatible_*()` expect ints?