From 6f1071f5ed6bd552378b2b70cd685b74e7f9e43d Mon Sep 17 00:00:00 2001
From: Pavel Rappo <prappo@openjdk.org>
Date: Thu, 17 Aug 2023 07:43:07 +0000
Subject: [PATCH] 8314213: DocLint should warn about unknown standard tags

Reviewed-by: jjg
---
 .../formats/html/taglets/TagletManager.java       |  2 +-
 .../jdk/javadoc/internal/doclint/Checker.java     | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/taglets/TagletManager.java b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/taglets/TagletManager.java
index a4724f03e9d..392678be6d3 100644
--- a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/taglets/TagletManager.java
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/taglets/TagletManager.java
@@ -358,7 +358,7 @@ public class TagletManager {
             if (!name.isEmpty() && name.charAt(0) == '@') {
                 name = name.substring(1);
             }
-            if (! (standardTags.contains(name) || allTaglets.containsKey(name))) {
+            if (! (standardTags.contains(name) || allTaglets.containsKey(name))) { // defunct, see 8314213
                 if (standardTagsLowercase.contains(Utils.toLowerCase(name))) {
                     messages.warning(ch.getDocTreePath(tag), "doclet.UnknownTagLowercase", ch.getTagName(tag));
                     continue;
diff --git a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclint/Checker.java b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclint/Checker.java
index 2a4b6332f60..2f5631adbc9 100644
--- a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclint/Checker.java
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclint/Checker.java
@@ -41,6 +41,8 @@ import java.util.Objects;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import javax.lang.model.SourceVersion;
 import javax.lang.model.element.Element;
@@ -1138,10 +1140,23 @@ public class Checker extends DocTreePathScanner<Void, Void> {
     }
 
     private void checkUnknownTag(DocTree tree, String tagName) {
+        // if it were a standard tag, this method wouldn't be called:
+        // a standard tag is never represented by Unknown{Block,Inline}TagTree
+        assert tree instanceof UnknownBlockTagTree
+                || tree instanceof UnknownInlineTagTree;
+        assert !getStandardTags().contains(tagName);
+        // report an unknown tag only if custom tags are set, see 8314213
         if (env.customTags != null && !env.customTags.contains(tagName))
             env.messages.error(SYNTAX, tree, "dc.tag.unknown", tagName);
     }
 
+    private Set<String> getStandardTags() {
+        return Stream.of(DocTree.Kind.values())
+                .filter(k -> k.tagName != null) // not all DocTree represent tags
+                .map(k -> k.tagName)
+                .collect(Collectors.toUnmodifiableSet());
+    }
+
     @Override @DefinedBy(Api.COMPILER_TREE)
     public Void visitUses(UsesTree tree, Void ignore) {
         Element e = env.trees.getElement(env.currPath);