Fix to #605, http://bugs.mariadb.com/show_bug.cgi?id=605
Main assumed multi-byte characters in memory allocation but not outside of it so I removed that code and made it consistently assume single-byte characters.
Terminating character was added always to the last byte of string buffer regardless of the length of the string. Removed it and replaced malloc with calloc.
Moved variable introductions from the middle of the function to the beginning of it.