On 9/27/2022 7:38 AM, Derrick Stolee wrote:
> On 9/26/2022 5:55 PM, Junio C Hamano wrote:
>> "Derrick Stolee via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
>>
>>> @@ -1538,11 +1546,23 @@ static int maintenance_unregister(int argc, const char **argv, const char *prefi
>>> usage_with_options(builtin_maintenance_unregister_usage,
>>> options);
>>>
>>> - config_unset.git_cmd = 1;
>>> - strvec_pushl(&config_unset.args, "config", "--global", "--unset",
>>> - "--fixed-value", "maintenance.repo", maintpath, NULL);
>>> + for_each_string_list_item(item, list) {
>>> + if (!strcmp(maintpath, item->string)) {
>>> + found = 1;
>>> + break;
>>> + }
>>> + }
>>
>> Just out of curiosity, I ran this in a fresh repository and got a
>> segfault.
>
> Yikes! Thanks for catching. I think there was another instance in
> the 'register' code that I caught by tests, but I appreciate you
> catching this one.
>
>> An attached patch obviously fixes it, but I am wondering
>> if a better "fix" is to teach for_each_string_list_item() that it is
>> perfectly reasonable to see a NULL passed to it as the list, which
>> is a mere special case that the caller has a string list with 0
>> items on it.
>>
>> Thoughts?
>
> I agree that for_each_string_list_item() could handle NULL lists
> better, especially because it looks like a method and hides some
> details. Plus, wrapping the for-ish loop with an if statement is
> particularly ugly.
...
> I'll get a patch put together that changes the behavior of
> for_each_string_list_item() and adds the missing 'unregister' test
> so we can avoid this problem.
Of course, there is a reason why we don't check for NULL here,
and it's because -Werror=address complains when we use a non-pointer
value in the macro:
string-list.h:146:28: error: the address of ‘friendly_ref_names’ will always evaluate as ‘true’ [-Werror=address]
146 | for (item = (list) ? (list)->items : NULL; \
|
I tried searching for a way to suppress this error in a particular
case like this (perhaps using something like an attribute?), but I
couldn't find anything.
Thanks,
-Stolee
