bitcoin/bitcoin — pull request #896 by sipa (2012-02-25 18:06:31+00:00)
Title: Do not invoke anti-DoS system for invalid BIP16 transactions

Doing so would allow an attack on old nodes, which would relay a
standard transaction spending a BIP16 output in an invalid way,
until reaching a new node, which will disconnect their peer.

Reported by makomk on IRC.