(contd.) fix: if the max ordinal for a map value is zero then reserve…

… 1 bit for it instead of nothing

hollow/src/main/java/com/netflix/hollow/core/write/HollowMapTypeWriteState.java

@@ -185,7 +185,7 @@ private void calculateNumShards() {
         }
 
         long bitsPerKeyElement = 64 - Long.numberOfLeadingZeros(maxKeyOrdinal + 1);
-        long bitsPerValueElement = 64 - Long.numberOfLeadingZeros(maxValueOrdinal);
+        long bitsPerValueElement = maxValueOrdinal == 0 ? 1 : 64 - Long.numberOfLeadingZeros(maxValueOrdinal);
         long bitsPerMapSizeValue = 64 - Long.numberOfLeadingZeros(maxMapSize);
         long bitsPerMapPointer = 64 - Long.numberOfLeadingZeros(totalOfMapBuckets);