> On 16 Mar 2018, at 00:25, Eric Sunshine <sunshine@xxxxxxxxxxxxxx> wrote:
>
> On Thu, Mar 15, 2018 at 6:57 PM, <lars.schneider@xxxxxxxxxxxx> wrote:
>> The function same_encoding() checked only for alternative UTF-8 encoding
>> names. Teach it to check for all kinds of alternative UTF encoding
>> names.
>>
>> Signed-off-by: Lars Schneider <larsxschneider@xxxxxxxxx>
>> ---
>> diff --git a/utf8.c b/utf8.c
>> @@ -401,11 +401,27 @@ void strbuf_utf8_replace(struct strbuf *sb_src, int pos, int width,
>> +static int same_utf_encoding(const char *src, const char *dst)
>> +{
>> + if (istarts_with(src, "utf") && istarts_with(dst, "utf")) {
>> + /* src[3] or dst[3] might be '\0' */
>> + int i = (src[3] == '-' ? 4 : 3);
>> + int j = (dst[3] == '-' ? 4 : 3);
>> + return !strcasecmp(src+i, dst+j);
>> + }
>> + return 0;
>> +}
>
> Alternate implementation without magic numbers:
>
> if (iskip_prefix(src, "utf", &src) &&
> iskip_prefix(dst, "utf", &dst)) {
> if (*src == '-')
> src++;
> if (*dst == '-')
> dst++;
> return !strcasecmp(src, dst);
> }
> return 0;
>
> ... assuming you add an iskip_prefix() function (patterned after skip_prefix()).
If a reroll is necessary, then I can do this.
>> int is_encoding_utf8(const char *name)
>> {
>> if (!name)
>> return 1;
>> - if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
>> + if (same_utf_encoding("utf-8", name))
>> return 1;
>> return 0;
>> }
>> @@ -414,6 +430,8 @@ int same_encoding(const char *src, const char *dst)
>> {
>> if (is_encoding_utf8(src) && is_encoding_utf8(dst))
>> return 1;
>> + if (same_utf_encoding(src, dst))
>> + return 1;
>> return !strcasecmp(src, dst);
>> }
>
> This seems odd. I would have expected the newly-added generalized
> conditional to replace the original UTF-8-specific conditional, not
> supplement it. That is, shouldn't the entire function body be:
>
> if (same_utf_encoding(src, dst))
> return 1;
> return !strcasecmp(src, dst);
No, because is_encoding_utf8() returns "true" (=1) if the encoding
is NULL. That is not the case for UTF-16 et al. The caller of
same_encoding() might expect that behavior.
I could have moved the "UTF-8" == NULL assumption into
same_utf_encoding() but that did not feel right.
Does this make sense?
- Lars
