Off-by-one error in TranscodeFromStr (with ICU)

The char-Array charSizes in TranscodeFromStr::transcode is initialized with length csSize.
ICUTranscoder::transcodeFrom is called with maxChars=csSize+1.
For a fixed length encoding charSizes is set via memset(charSizes, fillSize, maxChars); writing one character too much.

To reproduce:
xercesc::TranscodeFromStr transcoder(reinterpret_cast<const XMLByte*>("foo"), 3, "ISO-8859-15");