This is how fragmentation tests used to happen:
A: conn.stackFrag = false
A->B: StartFragmentationTest
B->A: send large non-DF UDP packet
A->B: FragmentationReceived
B: conn.stackFrag = true
conn.stackFrag = true means "UDP packets sent to the other peer get
correctly fragmented and re-assembled".
Note how A clears its own stackFrag flag, but the test establishes
whether fragmentation works for B->A, and ends up setting stackFrag on
B. Not only is this weird, it also means that if A previously had
stackFrag=true, it will now start fragmenting packets until B
initiates a fragmentation test.
The new sequence is:
A: conn.stackFrag = false
A->B: send large non-DF UDP packet
B->A: FragmentationReceived
A: conn.stackFrag = true
Closes#746.
Matthias Radestock
fbf2208e80