CFStringEncoding: return IANA charset names in lowercase - #119
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CFStringEncoding: return IANA charset names in lowercase#119DTW-Thalion wants to merge 1 commit into
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ICU returns IANA names in uppercase, but Apple returns them in lowercase (utf-8, us-ascii, iso-8859-1). Lowercase the name before returning it.
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CFStringConvertEncodingToIANACharSetName returned ICU's canonical converter name (for example "ANSI_X3.4-1968" for US-ASCII and "ISO_8859-1:1987" for ISO Latin 1), but Apple returns the preferred IANA name in lowercase: "utf-8", "us-ascii", "iso-8859-1", "utf-16".
The MIME name is the preferred IANA name and matches Apple's output for the encodings that have one, so it is queried first, falling back to the plain IANA name otherwise. The result is lowercased. The lowercase copy is memoized by ICU's stable name pointer so repeated calls return the same constant string, preserving the previous behaviour of not making multiple copies.
Tests/CFStringEncoding/iana.m covers UTF-8, US-ASCII, ISO Latin 1 and UTF-16. The existing Tests/CFString/encodings.m assertion expected the uppercase "UTF-16" and has been corrected to "utf-16". The expected values match Apple CoreFoundation.