Fix handling of nested tags in UnrecognisedJavadocTag

PiperOrigin-RevId: 929262364

Author: cushon

core/src/main/java/com/google/errorprone/bugpatterns/javadoc/UnrecognisedJavadocTag.java

@@ -26,6 +26,8 @@
 import com.google.common.collect.ImmutableRangeSet;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Range;
+import com.google.common.collect.RangeSet;
+import com.google.common.collect.TreeRangeSet;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker;
@@ -92,7 +94,7 @@ private Description handle(@Nullable DocTreePath path, VisitorState state) {
   }
 
   private ImmutableRangeSet<Integer> findRecognisedTags(DocTreePath path, VisitorState state) {
-    ImmutableRangeSet.Builder<Integer> tags = ImmutableRangeSet.builder();
+    RangeSet<Integer> tags = TreeRangeSet.create();
     new DocTreePathScanner<Void, Void>() {
       @Override
       public Void visitLink(LinkTree linkTree, Void unused) {
@@ -108,7 +110,7 @@ public Void visitLiteral(LiteralTree literalTree, Void unused) {
         return super.visitLiteral(literalTree, null);
       }
     }.scan(path, null);
-    return tags.build();
+    return ImmutableRangeSet.copyOf(tags);
   }
 
   private static ImmutableSet<Integer> findTags(Comment comment) {

core/src/test/java/com/google/errorprone/bugpatterns/javadoc/UnrecognisedJavadocTagTest.java

@@ -113,4 +113,19 @@ class Test {}
             """)
         .doTest();
   }
+
+  @Test
+  public void nestedLink() {
+    helper
+        .addSourceLines(
+            "Test.java",
+            """
+            /**
+             * @deprecated use {@link Test with {@link Test}} instead.
+             */
+            @Deprecated
+            class Test {}
+            """)
+        .doTest();
+  }
 }