Fixes #1779 so that sending to multiple zaddrs no longer fails.

Commit 2eeb6b randomized the order of input and output notes,
but this is now known to prevent the chaining of multiple joinsplits
in a single transaction.  The root cause has yet to be determined.

This patch is a temporary fix and disables the shuffling of input
and output notes.  It also adds a chained joinsplit test to the
python qa test suite.

qa/rpc-tests/wallet_protectcoinbase.py

@@ -148,5 +148,22 @@ class Wallet2Test (BitcoinTestFramework):
         # check balance
         assert_equal(self.nodes[2].getbalance(), 9)
 
+        # Check that chained joinsplits in a single tx are created successfully.
+        recipients = []
+        num_recipients = 3
+        amount_per_recipient = Decimal('0.002')
+        for i in xrange(0,num_recipients):
+            newzaddr = self.nodes[2].z_getnewaddress()
+            recipients.append({"address":newzaddr, "amount":amount_per_recipient})
+        myopid = self.nodes[0].z_sendmany(myzaddr, recipients)
+        self.wait_for_operationd_success(myopid)
+        self.sync_all()
+        self.nodes[1].generate(1)
+        self.sync_all()
+
+        # check balances
+        resp = self.nodes[2].z_gettotalbalance()
+        assert_equal(Decimal(resp["private"]), num_recipients * amount_per_recipient)
+
 if __name__ == '__main__':
     Wallet2Test ().main ()

src/primitives/transaction.cpp

@@ -57,8 +57,10 @@ JSDescription JSDescription::Randomized(
     // Randomize the order of the inputs and outputs
     inputMap = {0, 1};
     outputMap = {0, 1};
-    MappedShuffle(inputs.begin(), inputMap.begin(), ZC_NUM_JS_INPUTS, gen);
-    MappedShuffle(outputs.begin(), outputMap.begin(), ZC_NUM_JS_OUTPUTS, gen);
+    if (gen) {
+        MappedShuffle(inputs.begin(), inputMap.begin(), ZC_NUM_JS_INPUTS, gen);
+        MappedShuffle(outputs.begin(), outputMap.begin(), ZC_NUM_JS_OUTPUTS, gen);
+    }
 
     return JSDescription(
         params, pubKeyHash, anchor, inputs, outputs,

src/wallet/asyncrpcoperation_sendmany.cpp

@@ -875,6 +875,7 @@ Object AsyncRPCOperation_sendmany::perform_joinsplit(
             {info.vjsout[0], info.vjsout[1]};
     boost::array<size_t, ZC_NUM_JS_INPUTS> inputMap;
     boost::array<size_t, ZC_NUM_JS_OUTPUTS> outputMap;
+    std::function<int(int)> emptyFunc;
     JSDescription jsdesc = JSDescription::Randomized(
             *pzcashParams,
             joinSplitPubKey_,
@@ -885,7 +886,9 @@ Object AsyncRPCOperation_sendmany::perform_joinsplit(
             outputMap,
             info.vpub_old,
             info.vpub_new,
-            !this->testmode);
+            !this->testmode,
+            // Temporary fix for #1779 is to disable shuffling of inputs and outputs.
+            emptyFunc);
 
     if (!(jsdesc.Verify(*pzcashParams, joinSplitPubKey_))) {
         throw std::runtime_error("error verifying joinsplit");