Retry on checksum failures?

[David Evans]

After updating gimp2 to 2.6.2 last night, an incidence was reported this
morning of checksum failure
during a fetch from one site out of many on the port's master_sites
list.  Fetches from other sites on
the list were successful and so it appears that this one site had a
bogus copy of the distribution on
its server.  Nonetheless, the attempt to fetch failed with no recourse
for the user other than to
remove the offending server from the Portfile.  Not something that the
casual user of MacPorts
should be expected to do.

I wonder if it would be a difficult thing to modify port to retry with
other sites on the list until
a successful fetch occurs or all listed sites are exhausted?  Isn't this
the behavior when a fetch
from one of the master_sites fails for other reasons? (timeout, file
doesn't exist, etc)?

Seems that this would make fetches more reliable to the end user without
compromising verification of the
validity of the distribution.

Dave