> On 06 Mar 2018, at 02:23, Junio C Hamano <gitster@xxxxxxxxx> wrote:
>
> Lars Schneider <larsxschneider@xxxxxxxxx> writes:
>
>>> On 05 Mar 2018, at 22:50, Junio C Hamano <gitster@xxxxxxxxx> wrote:
>>>
>>> lars.schneider@xxxxxxxxxxxx writes:
>>>
>>>> +static int validate_encoding(const char *path, const char *enc,
>>>> + const char *data, size_t len, int die_on_error)
>>>> +{
>>>> + if (!memcmp("UTF-", enc, 4)) {
>>>
>>> Does the caller already know that enc is sufficiently long that
>>> using memcmp is safe?
>>
>> No :-(
>>
>> Would you be willing to squash that in?
>>
>> if (strlen(enc) > 4 && !memcmp("UTF-", enc, 4)) {
>>
>> I deliberately used "> 4" as plain "UTF-" is not even valid.
>
> I'd rather not. The code does not have to even look at 6th and
> later bytes in the enc[] even if it wanted to reject "UTF-" followed
> by nothing, but use of strlen() forces it to look at everything.
>
> Stepping back, shouldn't
>
> if (starts_with(enc, "UTF-")
>
> be sufficient? If you really care about the case where "UTF-" alone
> comes here, you could write
>
> if (starts_with(enc, "UTF-") && enc[4])
>
> but I do not think "&& enc[4]" is even needed. The functions called
> from this block would not consider "UTF-" alone as something valid
> anyway, so with that "&& enf[4]" we would be piling more code only
> for invalid/rare case.
Agreed, "if (starts_with(enc, "UTF-"))" is sufficient. Can you squash
that in? Thanks for pointing me to starts_with() as I forgot about this
function!
- Lars
