Additional z_sendmany test cases

Also improve error messages.

qa/rpc-tests/wallet_z_sendmany.py

@@ -339,6 +339,10 @@ class WalletZSendmanyTest(BitcoinTestFramework):
             opid = self.nodes[1].z_sendmany(n1ua0, recipients, 1, 0, policy)
             wait_and_assert_operationid_status(self.nodes[1], opid, 'failed', msg)
 
+        # If we try to send just a bit less than we have, it will fail, complaining about dust
+        opid = self.nodes[1].z_sendmany(n1ua0, [{"address":n0ua0, "amount":3.9999999}], 1, 0, 'AllowLinkingAccountAddresses')
+        wait_and_assert_operationid_status(self.nodes[1], opid, 'failed', 'Insufficient funds: have 4.00, need 0.00000044 more to avoid creating invalid change output 0.0000001 (dust threshold is 0.00000054).')
+
         # Once we provide a sufficiently-weak policy, the transaction succeeds.
         opid = self.nodes[1].z_sendmany(n1ua0, recipients, 1, 0, 'AllowLinkingAccountAddresses')
         wait_and_assert_operationid_status(self.nodes[1], opid)
@@ -359,6 +363,20 @@ class WalletZSendmanyTest(BitcoinTestFramework):
         assert_equal(self.nodes[1].z_getbalance(n1ua0), 1)
         assert_equal(self.nodes[1].z_getbalance(n1ua1), 1)
 
+        #
+        # Test Orchard-only UA before NU5
+        #
+
+        n0orchard_only = self.nodes[0].z_getaddressforaccount(n0account0, ["orchard"])['address']
+        recipients = [{"address":n0orchard_only, "amount":1}]
+        for (policy, msg) in [
+            ('FullPrivacy', 'Could not send to a shielded receiver of a unified address without spending funds from a different pool, which would reveal transaction amounts. THIS MAY AFFECT YOUR PRIVACY. Resubmit with the `privacyPolicy` parameter set to `AllowRevealedAmounts` or weaker if you wish to allow this transaction to proceed anyway.'),
+            ('AllowRevealedAmounts', 'This transaction would send to a transparent receiver of a unified address, which is not enabled by default because it will publicly reveal transaction recipients and amounts. THIS MAY AFFECT YOUR PRIVACY. Resubmit with the `privacyPolicy` parameter set to `AllowRevealedRecipients` or weaker if you wish to allow this transaction to proceed anyway.'),
+            ('AllowRevealedRecipients', 'Could not send to an Orchard-only receiver, despite a lax privacy policy. Either there are insufficent non-Sprout funds, or NU5 has not been activated yet.'),
+        ]:
+            opid = self.nodes[1].z_sendmany(n1ua0, recipients, 1, 0, policy)
+            wait_and_assert_operationid_status(self.nodes[1], opid, 'failed', msg)
+
         #
         # Test NoPrivacy policy
         #
@@ -392,6 +410,19 @@ class WalletZSendmanyTest(BitcoinTestFramework):
         self.nodes[1].generate(10)
         self.sync_all()
 
+        #
+        # Test Orchard-only UA with insufficient non-Sprout funds
+        #
+
+        recipients = [{"address":n0orchard_only, "amount":100}]
+        for (policy, msg) in [
+            ('FullPrivacy', 'Could not send to a shielded receiver of a unified address without spending funds from a different pool, which would reveal transaction amounts. THIS MAY AFFECT YOUR PRIVACY. Resubmit with the `privacyPolicy` parameter set to `AllowRevealedAmounts` or weaker if you wish to allow this transaction to proceed anyway.'),
+            ('AllowRevealedAmounts', 'This transaction would send to a transparent receiver of a unified address, which is not enabled by default because it will publicly reveal transaction recipients and amounts. THIS MAY AFFECT YOUR PRIVACY. Resubmit with the `privacyPolicy` parameter set to `AllowRevealedRecipients` or weaker if you wish to allow this transaction to proceed anyway.'),
+            ('AllowRevealedRecipients', 'Could not send to an Orchard-only receiver, despite a lax privacy policy. Either there are insufficent non-Sprout funds, or NU5 has not been activated yet.'),
+        ]:
+            opid = self.nodes[1].z_sendmany(n1ua0, recipients, 1, 0, policy)
+            wait_and_assert_operationid_status(self.nodes[1], opid, 'failed', msg)
+
         #
         # Test AllowRevealedAmounts policy
         #

src/wallet/asyncrpcoperation_common.cpp

@@ -139,14 +139,24 @@ void ThrowInputSelectionError(
                     FormatMoney(err.available - err.required)));
         },
         [](const ExcessOrchardActionsError& err) {
+            std::string side;
+            switch (err.side) {
+                case ActionSide::Input:
+                    side = "inputs";
+                case ActionSide::Output:
+                    side = "outputs";
+                case ActionSide::Both:
+                    side = "actions";
+            };
             throw JSONRPCError(
                 RPC_INVALID_PARAMETER,
                 strprintf(
-                    "Attempting to spend %u Orchard notes would exceed the current limit "
+                    "Including %u Orchard %s would exceed the current limit "
                     "of %u notes, which exists to prevent memory exhaustion. Restart with "
                     "`-orchardactionlimit=N` where N >= %u to allow the wallet to attempt "
                     "to construct this transaction.",
                     err.orchardNotes,
+                    side,
                     err.maxNotes,
                     err.orchardNotes));
         }

src/wallet/wallet_tx_builder.cpp

@@ -307,7 +307,10 @@ InputSelectionResult WalletTxBuilder::ResolveInputsAndPayments(
     auto resolved = Payments(resolvedPayments);
 
     if (orchardOutputs > this->maxOrchardActions) {
-        return ExcessOrchardActionsError(orchardOutputs, this->maxOrchardActions);
+        return ExcessOrchardActionsError(
+                ActionSide::Output,
+                orchardOutputs,
+                this->maxOrchardActions);
     }
 
     // Set the dust threshold so that we can select enough inputs to avoid
@@ -343,7 +346,10 @@ InputSelectionResult WalletTxBuilder::ResolveInputsAndPayments(
     }
 
     if (spendableMut.orchardNoteMetadata.size() > this->maxOrchardActions) {
-        return ExcessOrchardActionsError(spendableMut.orchardNoteMetadata.size(), this->maxOrchardActions);
+        return ExcessOrchardActionsError(
+                ActionSide::Input,
+                spendableMut.orchardNoteMetadata.size(),
+                this->maxOrchardActions);
     }
 
     return InputSelection(resolved, anchorHeight);

src/wallet/wallet_tx_builder.h

@@ -260,12 +260,20 @@ public:
         available(available), required(required) { }
 };
 
+enum ActionSide {
+    Input,
+    Output,
+    Both,
+};
+
 class ExcessOrchardActionsError {
 public:
+    ActionSide side;
     uint32_t orchardNotes;
     uint32_t maxNotes;
 
-    ExcessOrchardActionsError(uint32_t orchardNotes, uint32_t maxNotes): orchardNotes(orchardNotes), maxNotes(maxNotes) { }
+    ExcessOrchardActionsError(ActionSide side, uint32_t orchardNotes, uint32_t maxNotes):
+        side(side), orchardNotes(orchardNotes), maxNotes(maxNotes) { }
 };
 
 typedef std::variant<