core/forkid: fix off-by-one bug (#22879)

* forkid: added failing test

* forkid: fixed off-by-one bug

core/forkid/forkid.go

@@ -155,7 +155,7 @@ func newFilter(config *params.ChainConfig, genesis common.Hash, headfn func() ui
 		for i, fork := range forks {
 			// If our head is beyond this fork, continue to the next (we have a dummy
 			// fork of maxuint64 as the last item to always fail this check eventually).
-			if head > fork {
+			if head >= fork {
 				continue
 			}
 			// Found the first unpassed fork block, check if our current state matches

core/forkid/forkid_test.go

@@ -163,6 +163,10 @@ func TestValidation(t *testing.T) {
 		// neither forks passed at neither nodes, they may mismatch, but we still connect for now.
 		{7279999, ID{Hash: checksumToBytes(0xa00bc324), Next: math.MaxUint64}, nil},
 
+		// Local is mainnet exactly on Petersburg, remote announces Byzantium + knowledge about Petersburg. Remote
+		// is simply out of sync, accept.
+		{7280000, ID{Hash: checksumToBytes(0xa00bc324), Next: 7280000}, nil},
+
 		// Local is mainnet Petersburg, remote announces Byzantium + knowledge about Petersburg. Remote
 		// is simply out of sync, accept.
 		{7987396, ID{Hash: checksumToBytes(0xa00bc324), Next: 7280000}, nil},