notnull

platform/usageView/src/com/intellij/usages/UsageInfo2UsageAdapter.java

@@ -36,6 +36,7 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.*;
 import com.intellij.reference.SoftReference;
 import com.intellij.usageView.UsageInfo;
+import com.intellij.usageView.UsageViewBundle;
 import com.intellij.usages.rules.*;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.IncorrectOperationException;
@@ -465,7 +466,7 @@ public class UsageInfo2UsageAdapter implements UsageInModule,
         return s;
       }
     }
-    return "";
+    return UsageViewBundle.message("node.invalid");
   }
 
   @Override

platform/usageView/src/com/intellij/usages/impl/GroupNode.java

@@ -54,13 +54,18 @@ public class GroupNode extends Node implements Navigatable, Comparable<GroupNode
 
   @Override
   protected void updateNotify() {
-    myGroup.update();
+    if (myGroup != null) {
+      myGroup.update();
+    }
   }
 
   public String toString() {
     String result = "";
-    if (myGroup != null) result += myGroup.getText(null);
-    return children == null ? result : result + children.toString();
+    if (myGroup != null) result = myGroup.getText(null);
+    if (children == null) {
+      return result;
+    }
+    return result + children.subList(0, Math.min(10, children.size())).toString();
   }
 
   public GroupNode addGroup(@NotNull UsageGroup group, int ruleIndex, @NotNull Consumer<Runnable> edtQueue) {
@@ -340,7 +345,7 @@ public class GroupNode extends Node implements Navigatable, Comparable<GroupNode
   }
 
   @Override
-  protected String getText(UsageView view) {
+  protected String getText(@NotNull UsageView view) {
     return myGroup.getText(view);
   }
 

platform/usageView/src/com/intellij/usages/impl/UsageNode.java

@@ -89,7 +89,7 @@ public class UsageNode extends Node implements Comparable<UsageNode>, Navigatabl
   }
 
   @Override
-  protected String getText(final UsageView view) {
+  protected String getText(@NotNull final UsageView view) {
     try {
       return myUsage.getPresentation().getPlainText();
     }

platform/usageView/src/com/intellij/usages/impl/UsageTargetNode.java

@@ -54,7 +54,7 @@ public class UsageTargetNode extends Node {
   }
 
   @Override
-  protected String getText(final UsageView view) {
+  protected String getText(@NotNull final UsageView view) {
     return myTarget.getPresentation().getPresentableText();
   }