Basically, i grepped for zlib.c and deflate.c (and i think libz.c as well). As i said, my check was very simplistic. It didn't start as "which packages have a problem", but more along the lines of "let's estimate the size of the problem".
I was limited on time i could spend on this. As best as i could, i tried compiling a list of maintainers email adresses and send them a mail, then posted this thread on PM. After that, i had to go back to my regularly scheduled slavery.
perl -e 'use Crypt::Digest::SHA256 qw[sha256_hex]; print substr(sha256_hex("the Answer To Life, The Universe And Everything"), 6, 2), "\n";'