Merge pull request #277 from corydickson/tally-votes-circuit-initialize

If it's the first batch ensure zero tally commitment

circuits/circom/tallyVotes.circom

@@ -132,12 +132,18 @@ template TallyVotes(
         voteTree[i].root === ballots[i][BALLOT_VO_ROOT_IDX];
     }
 
+    component isFirstBatch = IsZero();
+    isFirstBatch.in <== batchStartIndex;
+
+    component iz = IsZero();
+    iz.in <== isFirstBatch.out;
+
     //  ----------------------------------------------------------------------- 
     // Tally the new results
     component resultCalc[numVoteOptions];
     for (var i = 0; i < numVoteOptions; i ++) {
         resultCalc[i] = CalculateTotal(batchSize + 1);
-        resultCalc[i].nums[batchSize] <== currentResults[i];
+        resultCalc[i].nums[batchSize] <== currentResults[i] * iz.out;
         for (var j = 0; j < batchSize; j ++) {
             resultCalc[i].nums[j] <== votes[j][i];
         }
@@ -163,9 +169,6 @@ template TallyVotes(
         }
     }
 
-    component isFirstBatch = IsZero();
-    isFirstBatch.in <== batchStartIndex;
-
     // Verify the current and new tally
     component rcv = ResultCommitmentVerifier(voteOptionTreeDepth);
     rcv.isFirstBatch <== isFirstBatch.out;