From 045b5445b20fa3d2841d74846685919ceeea5e8d Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Wed, 1 Jun 2011 15:11:57 +0200
Subject: [PATCH] after common prefix insertion, frozen items may suddenly
 disappear from the lookup model (EA-27207)

---
 .../com/intellij/codeInsight/lookup/impl/LookupImpl.java | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
index 07c24a6bde56..2385d0219070 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/lookup/impl/LookupImpl.java
@@ -378,7 +378,7 @@ public class LookupImpl extends LightweightHint implements LookupEx, Disposable
 
     final Pair<List<LookupElement>,Iterable<List<LookupElement>>> snapshot = myModel.getModelSnapshot();
 
-    final List<LookupElement> items = matchingItems(snapshot);
+    final LinkedHashSet<LookupElement> items = matchingItems(snapshot);
 
     checkMinPrefixLengthChanges(items);
 
@@ -389,7 +389,10 @@ public class LookupImpl extends LightweightHint implements LookupEx, Disposable
     LinkedHashSet<LookupElement> model = new LinkedHashSet<LookupElement>();
     model.addAll(getPrefixItems(items, true));
     model.addAll(getPrefixItems(items, false));
+
+    myFrozenItems.retainAll(items);
     model.addAll(myFrozenItems);
+
     addMostRelevantItems(model, snapshot.second);
     if (hasPreselected) {
       model.add(myPreselectedItem);
@@ -431,8 +434,8 @@ public class LookupImpl extends LightweightHint implements LookupEx, Disposable
     }
   }
 
-  private List<LookupElement> matchingItems(Pair<List<LookupElement>, Iterable<List<LookupElement>>> snapshot) {
-    final List<LookupElement> items = new ArrayList<LookupElement>();
+  private LinkedHashSet<LookupElement> matchingItems(Pair<List<LookupElement>, Iterable<List<LookupElement>>> snapshot) {
+    final LinkedHashSet<LookupElement> items = new LinkedHashSet<LookupElement>();
     for (LookupElement element : snapshot.first) {
       if (prefixMatches(element)) {
         items.add(element);