for (int i = 0; i < offset; i++) if (new_chars[i] != buffer[i]) throw new EncodingChangeException ("character mismatch (new: " + new_chars[i] + " [0x"
for (int i = 0; i < offset; i++) if (new_chars[i] != buffer[i]) throw new EncodingChangeException ("character mismatch (new: " + new_chars[i] + " [0x"