-The result is passed back in the buffer; it is usually going to be added to
-some other string. In order to be sure there is going to be no overflow,
-restrict the length of the input to 1/4 of the buffer size - this allows for
-every single character to be quoted or encoded without overflowing, and that
-wouldn't happen because of amalgamation. If the phrase is too long, return a
-fixed string.