addressing pr comments, etc.

Author: benwtrent

server/src/main/java/org/elasticsearch/index/codec/vectors/IVFVectorsReader.java

@@ -286,7 +286,7 @@ public final void search(String field, float[] target, KnnCollector knnCollector
         // Note, numCollected is doing the bare minimum here.
         // TODO do we need to handle nested doc counts similarly to how we handle
         // filtering? E.g. keep exploring until we hit an expected number of parent documents vs. child vectors?
-        while (centroidQueue.size() > 0 && centroidsVisited < nProbe && knnCollectorImpl.numCollected() < knnCollector.k()) {
+        while (centroidQueue.size() > 0 && (centroidsVisited < nProbe || knnCollectorImpl.numCollected() < knnCollector.k())) {
             ++centroidsVisited;
             // todo do we actually need to know the score???
             int centroidOrdinal = centroidQueue.pop();

server/src/main/java/org/elasticsearch/search/vectors/IVFKnnFloatVectorQuery.java

@@ -80,9 +80,12 @@ protected TopDocs approximateSearch(
         KnnCollectorManager knnCollectorManager
     ) throws IOException {
         KnnCollector knnCollector = knnCollectorManager.newCollector(visitedLimit, searchStrategy, context);
+        if (knnCollector == null) {
+            return NO_RESULTS;
+        }
         LeafReader reader = context.reader();
         FloatVectorValues floatVectorValues = reader.getFloatVectorValues(field);
-        if (floatVectorValues == null || knnCollector == null) {
+        if (floatVectorValues == null) {
             FloatVectorValues.checkField(reader, field);
             return NO_RESULTS;
         }

server/src/test/java/org/elasticsearch/search/vectors/AbstractDiversifyingChildrenIVFKnnVectorQueryTestCase.java

@@ -93,7 +93,7 @@ static Document makeParent(int[] children) {
     @Before
     public void setUp() throws Exception {
         super.setUp();
-        format = new IVFVectorsFormat(128);
+        format = new IVFVectorsFormat(random().nextInt(IVFVectorsFormat.MIN_VECTORS_PER_CLUSTER, IVFVectorsFormat.MAX_VECTORS_PER_CLUSTER));
     }
 
     abstract Query getDiversifyingChildrenKnnQuery(