--- a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/markup/Links.java	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/markup/Links.java	Thu Oct 17 20:53:35 2019 +0100
@@ -100,7 +100,7 @@
      * @return a content tree for the marker anchor
      */
     public Content createAnchor(String name, Content content) {
-        return HtmlTree.A_ID(name, (content == null ? EMPTY_COMMENT : content));
+        return HtmlTree.A_ID(getName(name), (content == null ? EMPTY_COMMENT : content));
     }
 
     private static final Content EMPTY_COMMENT = new Comment(" ");
@@ -312,7 +312,7 @@
      * @return a valid HTML name
      */
     public String getName(String name) {
-        return name.replaceAll(" +", "");
+        return name.replaceAll("\\s+", "");
     }
 
 }