I wrote:
> Jeff Davis <pgsql(at)j-davis(dot)com> writes:
>> That's so bizarre that I have to guess that it's a perl bug.
> I agree.
Oh! No, it's a "feature": man perlop quoth
The empty pattern "//"
If the PATTERN evaluates to the empty string, the last
successfully matched regular expression is used instead. In
this case, only the "g" and "c" flags on the empty pattern are
honored; the other flags are taken from the original pattern.
If no match has previously succeeded, this will (silently) act
instead as a genuine empty pattern (which will always match).
So we actually need to find and nuke all of these, not just the one
that's causing trouble.
regards, tom lane