I was thinking about the case of the reverse scan, and it occurred to me
that if the character that followed the Meta matched a normal character
in the other string, a reverse scan could end up in the middle of a meta
sequence.  This patch fixes this.  Note that this code depends on the
(apparent) fact that a meta char cannot be followed by the same value
(e.g. we must be sure that when we see a meta value, it is the start of
a meta sequence and not the end).

..wayne..