8026368: doclint does not report empty tags when tag closed implicitly

Reviewed-by: darcy

langtools/src/share/classes/com/sun/tools/doclint/Checker.java

@@ -213,6 +213,7 @@ public class Checker extends DocTreePathScanner<Void, Void> {
     public Void visitDocComment(DocCommentTree tree, Void ignore) {
         super.visitDocComment(tree, ignore);
         for (TagStackItem tsi: tagStack) {
+            warnIfEmpty(tsi, null);
             if (tsi.tree.getKind() == DocTree.Kind.START_ELEMENT
                     && tsi.tag.endKind == HtmlTag.EndKind.REQUIRED) {
                 StartElementTree t = (StartElementTree) tsi.tree;
@@ -270,7 +271,6 @@ public class Checker extends DocTreePathScanner<Void, Void> {
 
     @Override
     public Void visitStartElement(StartElementTree tree, Void ignore) {
-        markEnclosingTag(Flag.HAS_ELEMENT);
         final Name treeName = tree.getName();
         final HtmlTag t = HtmlTag.get(treeName);
         if (t == null) {
@@ -279,7 +279,10 @@ public class Checker extends DocTreePathScanner<Void, Void> {
             boolean done = false;
             for (TagStackItem tsi: tagStack) {
                 if (tsi.tag.accepts(t)) {
-                    while (tagStack.peek() != tsi) tagStack.pop();
+                    while (tagStack.peek() != tsi) {
+                        warnIfEmpty(tagStack.peek(), null);
+                        tagStack.pop();
+                    }
                     done = true;
                     break;
                 } else if (tsi.tag.endKind != HtmlTag.EndKind.OPTIONAL) {
@@ -288,9 +291,13 @@ public class Checker extends DocTreePathScanner<Void, Void> {
                 }
             }
             if (!done && HtmlTag.BODY.accepts(t)) {
-                tagStack.clear();
+                while (!tagStack.isEmpty()) {
+                    warnIfEmpty(tagStack.peek(), null);
+                    tagStack.pop();
+                }
             }
 
+            markEnclosingTag(Flag.HAS_ELEMENT);
             checkStructure(tree, t);
 
             // tag specific checks
@@ -447,12 +454,7 @@ public class Checker extends DocTreePathScanner<Void, Void> {
                                         "dc.no.summary.or.caption.for.table");
                             }
                     }
-                    if (t.flags.contains(HtmlTag.Flag.EXPECT_CONTENT)
+                    warnIfEmpty(top, tree);
-                            && !top.flags.contains(Flag.HAS_TEXT)
-                            && !top.flags.contains(Flag.HAS_ELEMENT)
-                            && !top.flags.contains(Flag.HAS_INLINE_TAG)) {
-                        env.messages.warning(HTML, tree, "dc.tag.empty", treeName);
-                    }
                     tagStack.pop();
                     done = true;
                     break;
@@ -485,6 +487,20 @@ public class Checker extends DocTreePathScanner<Void, Void> {
 
         return super.visitEndElement(tree, ignore);
     }
+
+    void warnIfEmpty(TagStackItem tsi, DocTree endTree) {
+        if (tsi.tag != null && tsi.tree instanceof StartElementTree) {
+            if (tsi.tag.flags.contains(HtmlTag.Flag.EXPECT_CONTENT)
+                    && !tsi.flags.contains(Flag.HAS_TEXT)
+                    && !tsi.flags.contains(Flag.HAS_ELEMENT)
+                    && !tsi.flags.contains(Flag.HAS_INLINE_TAG)) {
+                DocTree tree = (endTree != null) ? endTree : tsi.tree;
+                Name treeName = ((StartElementTree) tsi.tree).getName();
+                env.messages.warning(HTML, tree, "dc.tag.empty", treeName);
+            }
+        }
+    }
+
     // </editor-fold>
 
     // <editor-fold defaultstate="collapsed" desc="HTML attributes">

langtools/test/tools/doclint/HtmlAttrsTest.java

@@ -10,7 +10,7 @@
 /** */
 public class HtmlAttrsTest {
     /**
-     * <p xyz>
+     * <p xyz> text </p>
      */
     public void unknown() { }
 

langtools/test/tools/doclint/HtmlAttrsTest.out

@@ -1,5 +1,5 @@
 HtmlAttrsTest.java:13: error: unknown attribute: xyz
-     * <p xyz>
+     * <p xyz> text </p>
           ^
 HtmlAttrsTest.java:18: warning: attribute obsolete: name
      * <img name="x" alt="alt">

langtools/test/tools/doclint/tidy/BadEnd.out

@@ -1,6 +1,9 @@
 BadEnd.java:14: warning: nested tag not allowed: <code>
  * <code> text <code>
                ^
+BadEnd.java:14: warning: empty <code> tag
+ * <code> text <code>
+               ^
 BadEnd.java:14: error: element not closed: code
  * <code> text <code>
                ^
@@ -14,4 +17,4 @@ BadEnd.java:13: error: element not closed: a
  * <a name="here"> text <a>
    ^
 4 errors
-1 warning
+2 warnings

langtools/test/tools/doclint/tidy/TrimmingEmptyTag.java

@@ -1,6 +1,6 @@
 /*
  * @test /nodynamiccopyright/
- * @bug 8004832
+ * @bug 8004832 8026368
  * @summary Add new doclint package
  * @library ..
  * @build DocLintTester
@@ -26,4 +26,9 @@
  * <ul></ul>
  * <ul><li></li></ul>
  */
-public class TrimmingEmptyTag { }
+public class TrimmingEmptyTag {
+    /** <p> */
+    public void implicitParaEnd_endOfComment() { }
+    /** <p> <ul><li>text</ul> */
+    public void implicitParaEnd_nextBlockTag() { }
+}

langtools/test/tools/doclint/tidy/TrimmingEmptyTag.out

@@ -43,4 +43,10 @@ TrimmingEmptyTag.java:25: warning: empty <tt> tag
 TrimmingEmptyTag.java:26: warning: empty <ul> tag
  * <ul></ul>
        ^
-15 warnings
+TrimmingEmptyTag.java:30: warning: empty <p> tag
+    /** <p> */
+        ^
+TrimmingEmptyTag.java:32: warning: empty <p> tag
+    /** <p> <ul><li>text</ul> */
+        ^
+17 warnings