Backport of #9352 to the 0.13 branch.
Because in 0.13 we call MarkBlockAsReceived inside ProcessNewBlock(), this code is slightly different from the version in #9352 -- I put a comment that should explain everything.
utACK. Will test.
utACK 53b656f3558fe960d9328079ca18eb53418f2652
ACK.
ACK 53b656f
Milestone
0.13.2