--- a/langtools/src/share/classes/com/sun/tools/doclint/Checker.java	Wed Jan 16 17:40:28 2013 +0000
+++ b/langtools/src/share/classes/com/sun/tools/doclint/Checker.java	Wed Jan 16 10:29:52 2013 -0800
@@ -25,6 +25,7 @@
 
 package com.sun.tools.doclint;
 
+import com.sun.source.doctree.LiteralTree;
 import java.util.regex.Matcher;
 import com.sun.source.doctree.LinkTree;
 import java.net.URI;
@@ -359,9 +360,8 @@
             env.messages.error(HTML, tree, "dc.tag.unknown", treeName);
         } else if (t.endKind == HtmlTag.EndKind.NONE) {
             env.messages.error(HTML, tree, "dc.tag.end.not.permitted", treeName);
-        } else if (tagStack.isEmpty()) {
-            env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);
         } else {
+            boolean done = false;
             while (!tagStack.isEmpty()) {
                 TagStackItem top = tagStack.peek();
                 if (t == top.tag) {
@@ -383,6 +383,7 @@
                         env.messages.error(HTML, tree, "dc.text.not.allowed", treeName);
                     }
                     tagStack.pop();
+                    done = true;
                     break;
                 } else if (top.tag == null || top.tag.endKind != HtmlTag.EndKind.REQUIRED) {
                     tagStack.pop();
@@ -400,10 +401,15 @@
                         tagStack.pop();
                     } else {
                         env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);
+                        done = true;
                         break;
                     }
                 }
             }
+
+            if (!done && tagStack.isEmpty()) {
+                env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);
+            }
         }
 
         return super.visitEndElement(tree, ignore);
@@ -546,6 +552,19 @@
     }
 
     @Override
+    public Void visitLiteral(LiteralTree tree, Void ignore) {
+        if (tree.getKind() == DocTree.Kind.CODE) {
+            for (TagStackItem tsi: tagStack) {
+                if (tsi.tag == HtmlTag.CODE) {
+                    env.messages.warning(HTML, tree, "dc.tag.nested.not.allowed", "code");
+                    break;
+                }
+            }
+        }
+        return super.visitLiteral(tree, ignore);
+    }
+
+    @Override
     public Void visitParam(ParamTree tree, Void ignore) {
         boolean typaram = tree.isTypeParameter();
         IdentifierTree nameTree = tree.getName();

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/doclint/EndTagsTest.java	Wed Jan 16 10:29:52 2013 -0800
@@ -0,0 +1,39 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8006236
+ * @summary doclint: structural issue hidden
+ * @build DocLintTester
+ * @run main DocLintTester -Xmsgs:-html EndTagsTest.java
+ * @run main DocLintTester -ref EndTagsTest.out EndTagsTest.java
+ */
+
+/** */
+public class EndTagsTest {
+    /** <p>  <a name="a1"> text <img alt="image" src="image.png"> </a> </p> */
+    public void valid_all() { }
+
+    /** <p>  <a name="a2"> text <img alt="image" src="image.png"> </a> */
+    public void valid_omit_optional_close() { }
+
+    /** </a> */
+    public void invalid_missing_start() { }
+
+    /** <p> </a> */
+    public void invalid_missing_start_2() { }
+
+    /** <p> text </p> </a> */
+    public void invalid_missing_start_3() { }
+
+    /** <img alt="image" src="image.png"> </img> */
+    public void invalid_end() { }
+
+    /** <invalid> </invalid> */
+    public void unknown_start_end() { }
+
+    /** <invalid> */
+    public void unknown_start() { }
+
+    /** </invalid> */
+    public void unknown_end() { }
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/doclint/EndTagsTest.out	Wed Jan 16 10:29:52 2013 -0800
@@ -0,0 +1,25 @@
+EndTagsTest.java:18: error: unexpected end tag: </a>
+    /** </a> */
+        ^
+EndTagsTest.java:21: error: unexpected end tag: </a>
+    /** <p> </a> */
+            ^
+EndTagsTest.java:24: error: unexpected end tag: </a>
+    /** <p> text </p> </a> */
+                      ^
+EndTagsTest.java:27: error: invalid end tag: </img>
+    /** <img alt="image" src="image.png"> </img> */
+                                          ^
+EndTagsTest.java:30: error: unknown tag: invalid
+    /** <invalid> </invalid> */
+        ^
+EndTagsTest.java:30: error: unknown tag: invalid
+    /** <invalid> </invalid> */
+                  ^
+EndTagsTest.java:33: error: unknown tag: invalid
+    /** <invalid> */
+        ^
+EndTagsTest.java:36: error: unknown tag: invalid
+    /** </invalid> */
+        ^
+8 errors