LUCENE-2119: behave better if you pass Integer.MAX_VALUE as nDcos to search methods

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@887670 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -32,6 +32,10 @@ Bug fixes
   one of the threads before all changes are actually committed.
   (Sanne Grinovero via Mike McCandless)
 
+* LUCENE-2119: Don't throw NegativeArraySizeException if you pass
+  Integer.MAX_VALUE as nDocs to IndexSearcher search methods.  (Paul
+  Taylor via Mike McCandless)
+
 New features
 
 * LUCENE-2069: Added Unicode 4 support to CharArraySet. Due to the switch

src/java/org/apache/lucene/search/IndexSearcher.java

@@ -158,12 +158,14 @@ public class IndexSearcher extends Searcher {
 
   // inherit javadoc
   @Override
-  public TopDocs search(Weight weight, Filter filter, final int nDocs) throws IOException {
+  public TopDocs search(Weight weight, Filter filter, int nDocs) throws IOException {
 
     if (nDocs <= 0) {
       throw new IllegalArgumentException("nDocs must be > 0");
     }
 
+    nDocs = Math.min(nDocs, reader.maxDoc());
+
     TopScoreDocCollector collector = TopScoreDocCollector.create(nDocs, !weight.scoresDocsOutOfOrder());
     search(weight, filter, collector);
     return collector.topDocs();
@@ -186,9 +188,12 @@ public class IndexSearcher extends Searcher {
    * then pass that to {@link #search(Weight, Filter,
    * Collector)}.</p>
    */
-  public TopFieldDocs search(Weight weight, Filter filter, final int nDocs,
+  public TopFieldDocs search(Weight weight, Filter filter, int nDocs,
                              Sort sort, boolean fillFields)
       throws IOException {
+
+    nDocs = Math.min(nDocs, reader.maxDoc());
+
     TopFieldCollector collector = TopFieldCollector.create(sort, nDocs,
         fillFields, fieldSortDoTrackScores, fieldSortDoMaxScore, !weight.scoresDocsOutOfOrder());
     search(weight, filter, collector);

src/java/org/apache/lucene/util/PriorityQueue.java

@@ -85,8 +85,18 @@ public abstract class PriorityQueue<T> {
     if (0 == maxSize)
       // We allocate 1 extra to avoid if statement in top()
       heapSize = 2;
-    else
-      heapSize = maxSize + 1;
+    else {
+      if (maxSize == Integer.MAX_VALUE) {
+        // Don't wrap heapSize to -1, in this case, which
+        // causes a confusing NegativeArraySizeException.
+        // Note that very likely this will simply then hit
+        // an OOME, but at least that's more indicative to
+        // caller that this values is too big:
+        heapSize = Integer.MAX_VALUE;
+      } else {
+        heapSize = maxSize + 1;
+      }
+    }
     heap = (T[]) new Object[heapSize]; // T is unbounded type, so this unchecked cast works always
     this.maxSize = maxSize;