Fix for WI-6841 'Quick Documentation Lookup' bug

platform/lang-api/src/com/intellij/psi/PsiDocComment.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2000-2011 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.psi;
+
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * Implementers of this interface may provide their own way of finding an associated doc comment owner element
+ * which may be essential for languages other than Java.
+ *
+ * @author Rustam Vishnyakov
+ */
+public interface PsiDocComment extends PsiComment {
+  /**
+   * @return The element which this doc comment refers to or null if there is no such element.
+   */
+  @Nullable
+  PsiElement getOwner();
+}

platform/lang-impl/src/com/intellij/codeInsight/documentation/DocumentationManager.java

@@ -196,8 +196,8 @@ public class DocumentationManager {
       PsiComment comment = PsiTreeUtil.getParentOfType(element, PsiComment.class);
       if (comment == null) return;
 
-      element = comment.getParent();
-      assertSameProject(element);
+      element = comment instanceof PsiDocComment ? ((PsiDocComment)comment).getOwner() : comment.getParent();
+      if (element == null) return;
       //if (!(element instanceof PsiDocCommentOwner)) return null;
     }