KT-1051 Java interoperability completion - invalidating java packages strategy

compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/JavaElementFinder.java

@@ -140,8 +140,8 @@ public class JavaElementFinder extends PsiElementFinder {
         final List<JetFile> psiFiles = collectProjectJetFiles(project, GlobalSearchScope.allScope(project));
 
         for (JetFile psiFile : psiFiles) {
-            if (JetPsiUtil.getFQName(psiFile).startsWith(qualifiedName)) {
-                return new JetLightPackage(psiManager, qualifiedName);
+            if (QualifiedNamesUtil.isSubpackageOf(JetPsiUtil.getFQName(psiFile), qualifiedName)) {
+                return new JetLightPackage(psiManager, qualifiedName, psiFile.getNamespaceHeader());
             }
         }
 
@@ -160,7 +160,7 @@ public class JavaElementFinder extends PsiElementFinder {
 
             final String subPackageFQN = QualifiedNamesUtil.plusOneSegment(psiPackage.getQualifiedName(), jetRootNamespace);
             if (subPackageFQN != null) {
-                answer.add(new JetLightPackage(psiManager, subPackageFQN));
+                answer.add(new JetLightPackage(psiManager, subPackageFQN, psiFile.getNamespaceHeader()));
             }
         }
 

compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/JetLightPackage.java

@@ -10,18 +10,21 @@ import com.intellij.psi.impl.file.PsiPackageImpl;
  * @author Nikolay Krasko
  */
 public class JetLightPackage extends PsiPackageImpl {
-    public JetLightPackage(PsiManager manager, String qualifiedName) {
+
+    private final PsiElement namespaceElement;
+
+    public JetLightPackage(PsiManager manager, String qualifiedName, PsiElement namespaceElement) {
         super(manager, qualifiedName);
+        this.namespaceElement = namespaceElement;
     }
 
     @Override
     public PsiElement copy() {
-        return new JetLightPackage(getManager(), getQualifiedName());
+        return new JetLightPackage(getManager(), getQualifiedName(), namespaceElement);
     }
 
     @Override
     public boolean isValid() {
-        // TODO: invalidate properly
-        return super.isValid();
+        return namespaceElement.isValid();
     }
 }