UWIs must always be eliminated first

src/main/java/network/brightspots/rcv/Tabulator.java

@@ -509,6 +509,11 @@ private List<String> identifyWinners(
       throws TabulationAbortedException {
     List<String> selectedWinners = new LinkedList<>();
 
+    if (getCandidateSignum(UNDECLARED_WRITE_IN_OUTPUT_LABEL, currentRoundTally) != 0) {
+      // No winners can be selected while undeclared candidates are live
+      return selectedWinners;
+    }
+
     if (config.isMultiSeatBottomsUpWithThresholdEnabled()) {
       // if everyone meets the threshold, select them all as winners
       boolean allMeet =
@@ -636,8 +641,7 @@ private void selectWinners(
   private List<String> dropUndeclaredWriteIns(RoundTally currentRoundTally) {
     List<String> eliminated = new LinkedList<>();
     String label = UNDECLARED_WRITE_IN_OUTPUT_LABEL;
-    if (currentRoundTally.getCandidateTally(label) != null
-        && currentRoundTally.getCandidateTally(label).signum() == 1) {
+    if (getCandidateSignum(label, currentRoundTally) == 1) {
       eliminated.add(label);
       Logger.info(
           "Eliminated candidate \"%s\" in round %d because it represents undeclared write-ins. It "
@@ -647,6 +651,19 @@ private List<String> dropUndeclaredWriteIns(RoundTally currentRoundTally) {
     return eliminated;
   }
 
+  // Returns the signum of the tally for a given label, or 0 if the label is not
+  // in the current round
+  // param: label candidate ID
+  // param: currentRoundTally map of candidate IDs to their tally for a given round
+  // returns: signum of the candidate tally
+  private int getCandidateSignum(String label, RoundTally currentRoundTally) {
+    BigDecimal tally = currentRoundTally.getCandidateTally(label);
+    if (tally == null) {
+      return 0;
+    }
+    return tally.signum();
+  }
+
   // eliminate all candidates below a certain tally threshold
   // param: currentRoundTallyToCandidates map of tally to candidate IDs for a given round
   // returns: eliminated candidates

src/test/resources/network/brightspots/rcv/test_data/multi_seat_uwi_test/multi_seat_uwi_test_expected_summary.csv

@@ -16,16 +16,16 @@ Total Number of Ballots,15
 Number of Undervotes,0
 
 Rounds,Round 1 Votes,% of vote,transfer,Round 2 Votes,% of vote,transfer,Round 3 Votes,% of vote,transfer,Round 4 Votes,% of vote,transfer,Round 5 Votes,% of vote,transfer
-Eliminated,,,,Undeclared Write-ins,,,C,,,,,,,,
-Elected,A,,,,,,,,,B,,,,,
-A,6,40.0%,0.0000,6.0000,66.66%,0.0000,6.0000,120.0%,0.0000,6.0000,200.0%,0.0000,6.0000,,0
-B,3,20.0%,0,3,33.33%,0,3,60.0%,0,3,100.0%,0.0000,3.0000,,0
-C,2,13.33%,0,2,22.22%,0,2,40.0%,-2,0,0.0%,0,0,,0
-Undeclared Write-ins,4,26.66%,0,4,44.44%,-4,0,0.0%,0,0,0.0%,0,0,,0
-Active Ballots,15,,,9,,,5,,,3,,,0,,
+Eliminated,Undeclared Write-ins,,,,,,C,,,,,,,,
+Elected,,,,A,,,,,,B,,,,,
+A,6,40.0%,0,6,54.54%,0.0000,6.0000,120.0%,0.0000,6.0000,200.0%,0.0000,6.0000,,0
+B,3,20.0%,0,3,27.27%,0,3,60.0%,0,3,100.0%,0.0000,3.0000,,0
+C,2,13.33%,0,2,18.18%,0,2,40.0%,-2,0,0.0%,0,0,,0
+Undeclared Write-ins,4,26.66%,-4,0,0.0%,0,0,0.0%,0,0,0.0%,0,0,,0
+Active Ballots,15,,,11,,,5,,,3,,,0,,
 Current Round Threshold,6,,,6,,,6,,,6,,,6,,
 Inactive Ballots by Overvotes,0,,0,0,,0,0,,0,0,,0,0,,0
 Inactive Ballots by Skipped Rankings,0,,0,0,,0,0,,0,0,,0,0,,0
 Inactive Ballots by Exhausted Choices,0,,0,0,,0,0,,0,0,,0,0,,0
 Inactive Ballots by Repeated Rankings,0,,0,0,,0,0,,0,0,,0,0,,0
-Inactive Ballots Total,0,,0.0000,0.0000,,4.0000,4.0000,,2.0000,6.0000,,0.0000,6.0000,,0
+Inactive Ballots Total,0,,4,4,,0.0000,4.0000,,2.0000,6.0000,,0.0000,6.0000,,0

src/test/resources/network/brightspots/rcv/test_data/multi_seat_uwi_test/multi_seat_uwi_test_expected_summary.json

@@ -22,8 +22,10 @@
       "Undeclared Write-ins" : "4"
     },
     "tallyResults" : [ {
-      "elected" : "A",
-      "transfers" : { }
+      "eliminated" : "Undeclared Write-ins",
+      "transfers" : {
+        "exhausted" : "4"
+      }
     } ],
     "threshold" : "6"
   }, {
@@ -35,16 +37,13 @@
     },
     "round" : 2,
     "tally" : {
-      "A" : "6.0000",
+      "A" : "6",
       "B" : "3",
-      "C" : "2",
-      "Undeclared Write-ins" : "4"
+      "C" : "2"
     },
     "tallyResults" : [ {
-      "eliminated" : "Undeclared Write-ins",
-      "transfers" : {
-        "exhausted" : "4"
-      }
+      "elected" : "A",
+      "transfers" : { }
     } ],
     "threshold" : "6"
   }, {