Since the netpbm update was reverted in 836223f74, I'm closing this bug.
Mark- bug#19686: Bad source checksum in netpbm Marek Benc
- bug#19686: Bad source checksum in netpbm Andreas Enge
- bug#19686: Bad source checksum in netpbm Ricardo Wurmus
- bug#19686: Bad source checksum in netpbm Mark H Weaver
