Part of #1969. Changing min fee calculation also changes the dust threshold.

qa/rpc-tests/wallet_protectcoinbase.py

@@ -181,7 +181,7 @@ class WalletProtectCoinbaseTest (BitcoinTestFramework):
         amount = Decimal('10.0') - Decimal('0.00010000') - Decimal('0.00000001')    # this leaves change at 1 zatoshi less than dust threshold
         recipients.append({"address":self.nodes[0].getnewaddress(), "amount":amount })
         myopid = self.nodes[0].z_sendmany(mytaddr, recipients)
-        self.wait_and_assert_operationid_status(myopid, "failed", "Insufficient transparent funds, have 10.00, need 0.00000545 more to avoid creating invalid change output 0.00000001 (dust threshold is 0.00000546)")
+        self.wait_and_assert_operationid_status(myopid, "failed", "Insufficient transparent funds, have 10.00, need 0.00000053 more to avoid creating invalid change output 0.00000001 (dust threshold is 0.00000054)")
 
         # Send will fail because send amount is too big, even when including coinbase utxos
         errorString = ""

src/primitives/transaction.h

@@ -274,7 +274,7 @@ public:
         // to spend something, then we consider it dust.
         // A typical txout is 34 bytes big, and will
         // need a CTxIn of at least 148 bytes to spend:
-        // so dust is a txout less than 546 satoshis 
+        // so dust is a txout less than 54 satoshis
         // with default minRelayTxFee.
         size_t nSize = GetSerializeSize(SER_DISK,0)+148u;
         return 3*minRelayTxFee.GetFee(nSize);

src/test/transaction_tests.cpp

@@ -560,7 +560,7 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     string reason;
     BOOST_CHECK(IsStandardTx(t, reason));
 
-    t.vout[0].nValue = 501; // dust
+    t.vout[0].nValue = 53; // dust
     BOOST_CHECK(!IsStandardTx(t, reason));
 
     t.vout[0].nValue = 2730; // not dust
@@ -639,7 +639,7 @@ BOOST_AUTO_TEST_CASE(test_IsStandardV2)
     BOOST_CHECK(IsStandardTx(t, reason));
 
     // v2 transactions can still be non-standard for the same reasons as v1.
-    t.vout[0].nValue = 501; // dust
+    t.vout[0].nValue = 53; // dust
     BOOST_CHECK(!IsStandardTx(t, reason));
 
     // v3 is not standard.