test: test case where we can't afford fees.

In particular, make sure B can just afford it, then have the A add a
HTLC which means B can no longer afford the fees, and A should cover
it.

We do this by modifying the previous overlapping-fail test, but we
need to have B offer it the htlc before A does: racy in the normal
autocommit case.  So we do a manual commit here, always.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/test/test.sh

@@ -801,16 +801,18 @@ check_status $A_AMOUNT $A_FEE "" $B_AMOUNT $B_FEE ""
 SECRET2=1de08917a61cb2b62ed5937d38577f6a7bfe59c176781c6d8128018e8b5ccdfe
 RHASH2=`lcli1 dev-rhash $SECRET2 | sed 's/.*"\([0-9a-f]*\)".*/\1/'`
 
-# This means B will *just* afford it.
-HTLC_AMOUNT=$(($B_AMOUNT - $EXTRA_FEE))
-HTLCID2=`lcli1 newhtlc $ID2 $HTLC_AMOUNT $EXPIRY $RHASH2 | extract_id`
+# This means B will *just* afford it (but can't cover increased fees)
+HTLC_AMOUNT=$(($B_AMOUNT - $EXTRA_FEE / 2))
 HTLCID=`lcli2 newhtlc $ID1 $HTLC_AMOUNT $EXPIRY $RHASH | extract_id`
+# Make sure that's committed, in case lcli1 restarts.
+lcli2 commit $ID1 >/dev/null || true
 
+HTLCID2=`lcli1 newhtlc $ID2 $HTLC_AMOUNT $EXPIRY $RHASH2 | extract_id`
 [ ! -n "$MANUALCOMMIT" ] || lcli1 commit $ID2
 [ ! -n "$MANUALCOMMIT" ] || lcli2 commit $ID1
-[ ! -n "$MANUALCOMMIT" ] || lcli1 commit $ID2
 
-check_status $(($A_AMOUNT - $HTLC_AMOUNT - $EXTRA_FEE)) $(($A_FEE + $EXTRA_FEE)) "{ msatoshis : $HTLC_AMOUNT, expiry : { block : $EXPIRY }, rhash : $RHASH2 , state : SENT_ADD_ACK_REVOCATION } " 0 $(($B_FEE + $EXTRA_FEE)) "{ msatoshis : $HTLC_AMOUNT, expiry : { block : $EXPIRY }, rhash : $RHASH , state : RCVD_ADD_ACK_REVOCATION } "
+# A covers the extra part of the fee.
+check_status $(($A_AMOUNT - $HTLC_AMOUNT - $EXTRA_FEE - $EXTRA_FEE / 2)) $(($A_FEE + $EXTRA_FEE + $EXTRA_FEE / 2)) "{ msatoshis : $HTLC_AMOUNT, expiry : { block : $EXPIRY }, rhash : $RHASH2 , state : SENT_ADD_ACK_REVOCATION } " 0 $(($B_FEE + $EXTRA_FEE / 2)) "{ msatoshis : $HTLC_AMOUNT, expiry : { block : $EXPIRY }, rhash : $RHASH , state : RCVD_ADD_ACK_REVOCATION } "
 
 # Fail both, to reset.
 lcli1 failhtlc $ID2 $HTLCID 830