Markus Armbruster
e2ec3f9768
Known bugs in to_json(): * A start byte for a three-byte sequence followed by less than two continuation bytes is split into one-byte sequences. * Start bytes for sequences longer than three bytes get misinterpreted as start bytes for three-byte sequences. Continuation bytes beyond byte three become one-byte sequences. This means all characters outside the BMP are decoded incorrectly. * One-byte sequences with the MSB are put into the JSON string verbatim when char is unsigned, producing invalid UTF-8. When char is signed, they're replaced by "\\uFFFF" instead. This includes \xFE, \xFF, and stray continuation bytes. * Overlong sequences are happily accepted, unless screwed up by the bugs above. * Likewise, sequences encoding surrogate code points or noncharacters. * Unlike other control characters, ASCII DEL is not escaped. Except in overlong encodings. My rewrite fixes them as follows: * Malformed UTF-8 sequences are replaced. Except the overlong encoding \xC0\x80 of U+0000 is still accepted. Permits embedding NUL characters in C strings. This trick is known as "Modified UTF-8". * Sequences encoding code points beyond Unicode range are replaced. * Sequences encoding code points beyond the BMP produce a surrogate pair. * Sequences encoding surrogate code points are replaced. * Sequences encoding noncharacters are replaced. * ASCII DEL is now always escaped. The replacement character is U+FFFD. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
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