don't require java file copy to be java (EA-70418 - assert: PsiJavaFileBaseImpl.clone)

java/java-psi-impl/src/com/intellij/psi/impl/source/PsiJavaFileBaseImpl.java

@@ -50,7 +50,6 @@ import com.intellij.util.containers.MostlySingularMultiMap;
 import com.intellij.util.indexing.IndexingDataKeys;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -67,17 +66,6 @@ public abstract class PsiJavaFileBaseImpl extends PsiFileImpl implements PsiJava
     myResolveCache = CachedValuesManager.getManager(myManager.getProject()).createCachedValue(new MyCacheBuilder(this), false);
   }
 
-  @Override
-  @SuppressWarnings({"CloneDoesntDeclareCloneNotSupportedException"})
-  protected PsiJavaFileBaseImpl clone() {
-    PsiFileImpl clone = super.clone();
-    if (!(clone instanceof PsiJavaFileBaseImpl)) {
-      throw new AssertionError("Java file cloned as text: " + getTextLength() + "; " + getViewProvider());
-    }
-    clone.clearCaches();
-    return (PsiJavaFileBaseImpl)clone;
-  }
-
   @Override
   public void subtreeChanged() {
     super.subtreeChanged();

platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java

@@ -458,6 +458,8 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
     else if (myOriginalFile != null) {
       clone.myOriginalFile = myOriginalFile;
     }
+    
+    clone.clearCaches();
 
     return clone;
   }