Index: search/org/eclipse/jdt/internal/core/index/DiskIndex.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/index/DiskIndex.java,v
--- search/org/eclipse/jdt/internal/core/index/DiskIndex.java	9 Mar 2010 05:55:04 -0000	1.69
+++ search/org/eclipse/jdt/internal/core/index/DiskIndex.java	15 Apr 2010 06:29:02 -0000
@@ -132,11 +132,13 @@ 
 	}
 	return results;
 }
-private HashtableOfObject addQueryResult(HashtableOfObject results, char[] word, CategoryTable wordsToDocNumbers, MemoryIndex memoryIndex) throws IOException {
+private HashtableOfObject addQueryResult(HashtableOfObject results, char[] word, CategoryTable wordsToDocNumbers, MemoryIndex memoryIndex, boolean checkBeforeAdd) throws IOException {
 	// must skip over documents which have been added/changed/deleted in the memory index
 	if (results == null)
 		results = new HashtableOfObject(13);
-	EntryResult result = (EntryResult) results.get(word);
+	EntryResult result = null;
+	if (checkBeforeAdd)		
+		result = (EntryResult) results.get(word);
 	if (memoryIndex == null) {
 		if (result == null)
 			results.putUnsafely(word, new EntryResult(word, wordsToDocNumbers));
@@ -161,6 +163,7 @@ 
 	if (this.categoryOffsets == null) return null; // file is empty
 
 	HashtableOfObject results = null; // initialized if needed
+	boolean checkBeforeAdd = memoryIndex != null; // used to optimize adding the results 
 	if (key == null) {
 		for (int i = 0, l = categories.length; i < l; i++) {
 			CategoryTable wordsToDocNumbers = readCategoryTable(categories[i], true); // cache if key is null since its a definite match
@@ -170,7 +173,8 @@ 
 					results = new HashtableOfObject(wordsToDocNumbers.elementSize);
 				for (int j = 0, m = words.length; j < m; j++)
 					if (words[j] != null)
-						results = addQueryResult(results, words[j], wordsToDocNumbers, memoryIndex);
+						results = addQueryResult(results, words[j], wordsToDocNumbers, memoryIndex, checkBeforeAdd);
+				checkBeforeAdd = true;
 			}
 		}
 		if (results != null && this.cachedChunks == null)
@@ -180,8 +184,10 @@ 
 			case SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE:
 				for (int i = 0, l = categories.length; i < l; i++) {
 					CategoryTable wordsToDocNumbers = readCategoryTable(categories[i], false);
-					if (wordsToDocNumbers != null && wordsToDocNumbers.containsKey(key))
-						results = addQueryResult(results, key, wordsToDocNumbers, memoryIndex);
+					if (wordsToDocNumbers != null && wordsToDocNumbers.containsKey(key)) {
+						results = addQueryResult(results, key, wordsToDocNumbers, memoryIndex, checkBeforeAdd);
+						checkBeforeAdd = true;
+					}
 				}
 				break;
 			case SearchPattern.R_PREFIX_MATCH | SearchPattern.R_CASE_SENSITIVE:
@@ -192,8 +198,9 @@ 
 						for (int j = 0, m = words.length; j < m; j++) {
 							char[] word = words[j];
 							if (word != null && key[0] == word[0] && CharOperation.prefixEquals(key, word))
-								results = addQueryResult(results, word, wordsToDocNumbers, memoryIndex);
+								results = addQueryResult(results, word, wordsToDocNumbers, memoryIndex, checkBeforeAdd);
 						}
+						checkBeforeAdd = true;
 					}
 				}
 				break;
@@ -205,8 +212,9 @@ 
 						for (int j = 0, m = words.length; j < m; j++) {
 							char[] word = words[j];
 							if (word != null && Index.isMatch(key, word, matchRule))
-								results = addQueryResult(results, word, wordsToDocNumbers, memoryIndex);
+								results = addQueryResult(results, word, wordsToDocNumbers, memoryIndex, checkBeforeAdd);
 						}
+						checkBeforeAdd = true;
 					}
 				}
 		}