pytest: remove test_lockup_drain.

Since this was written, we now test if remote side would get into this situation and stop
it from happening, so the test doesn't work any more.

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

tests/test_pay.py

@@ -2810,31 +2810,6 @@ def test_channel_spendable_receivable_capped(node_factory, bitcoind):
     assert l2.rpc.listpeerchannels()['channels'][0]['receivable_msat'] == Millisatoshi(0xFFFFFFFF)
 
 
-@unittest.skipIf(True, "Test is extremely flaky")
-def test_lockup_drain(node_factory, bitcoind):
-    """Try to get channel into a state where opener can't afford fees on additional HTLC, so peer can't add HTLC"""
-    l1, l2 = node_factory.line_graph(2, opts={'may_reconnect': True})
-
-    # l1 sends all the money to l2 until even 1 msat can't get through.
-    total = l1.drain(l2)
-
-    # Even if feerate now increases 2x (30000), l2 should be able to send
-    # non-dust HTLC to l1.
-    l1.force_feerates(30000)
-    l2.pay(l1, total // 2)
-
-    # reset fees and send all back again
-    l1.force_feerates(15000)
-    l1.drain(l2)
-
-    # But if feerate increase just a little more, l2 should not be able to send
-    # non-fust HTLC to l1
-    l1.force_feerates(30002)  # TODO: Why does 30001 fail? off by one in C code?
-    wait_for(lambda: l1.rpc.listpeers()['peers'][0]['connected'])
-    with pytest.raises(RpcError, match=r".*Capacity exceeded.*"):
-        l2.pay(l1, total // 2)
-
-
 @unittest.skipIf(TEST_NETWORK != 'regtest', 'Assumes anchors')
 def test_htlc_too_dusty_outgoing(node_factory, bitcoind, chainparams):
     """ Try to hit the 'too much dust' limit, should fail the HTLC """