Safer dropping caches in ExternalAnnotationsManager.

java/java-impl/src/com/intellij/codeInsight/ExternalAnnotationsManagerImpl.java

@@ -91,13 +91,17 @@ public class ExternalAnnotationsManagerImpl extends BaseExternalAnnotationsManag
     connection.subscribe(ProjectTopics.PROJECT_ROOTS, new ModuleRootAdapter() {
       @Override
       public void rootsChanged(ModuleRootEvent event) {
-        myExternalAnnotations.clear();
-        annotationsFileToDataAndModificationStamp.clear();
-        myHasAnyAnnotationsRoots = ThreeState.UNSURE;
+        dropCache();
       }
     });
   }
 
+  @Override
+  protected void dropCache() {
+    super.dropCache();
+    myHasAnyAnnotationsRoots = ThreeState.UNSURE;
+  }
+
   @Override
   protected boolean hasAnyAnnotationsRoots() {
     if (myHasAnyAnnotationsRoots == ThreeState.UNSURE) {

java/java-psi-api/src/com/intellij/codeInsight/BaseExternalAnnotationsManager.java

@@ -262,6 +262,8 @@ public abstract class BaseExternalAnnotationsManager extends ExternalAnnotations
   }
 
   protected void dropCache() {
+    myExternalAnnotations.clear();
+    annotationsFileToDataAndModificationStamp.clear();
     cache.clear();
   }