Function svn_utf_cstring_from_utf8_fuzzy 

pub unsafe extern "C" fn svn_utf_cstring_from_utf8_fuzzy(
    src: *const c_char,
    pool: *mut apr_pool_t,
) -> *const c_char

Return a fuzzily native-encoded C string from utf8 C string @a src, allocated in @a pool. A fuzzy recoding leaves all 7-bit ascii characters the same, and substitutes “?\XXX” for others, where XXX is the unsigned decimal code for that character.

This function cannot error; it is guaranteed to return something. First it will recode as described above and then attempt to convert the (new) 7-bit UTF-8 string to native encoding. If that fails, it will return the raw fuzzily recoded string, which may or may not be meaningful in the client’s locale, but is (presumably) better than nothing.

Notes:

Improvement is possible, even imminent. The original problem was that if you converted a UTF-8 string (say, a log message) into a locale that couldn’t represent all the characters, you’d just get a static placeholder saying “[unconvertible log message]”. Then Justin Erenkrantz pointed out how on platforms that didn’t support conversion at all, “svn log” would still fail completely when it encountered unconvertible data.

Now for both cases, the caller can at least fall back on this function, which converts the message as best it can, substituting “?\XXX” escape codes for the non-ascii characters.

Ultimately, some callers may prefer the iconv “//TRANSLIT” option, so when we can detect that at configure time, things will change. Also, this should (?) be moved to apr/apu eventually.

See https://issues.apache.org/jira/browse/SVN-807 for details.