stapler-jelly currently depends on a patched version¹ of dom4j, the original of which was released thirteen years ago. Current releases support Java 8, etc.

A simple

diff --git a/jelly/pom.xml b/jelly/pom.xml
index 8aa4ec8d7..725f2ba56 100644
--- a/jelly/pom.xml
+++ b/jelly/pom.xml
@@ -32,9 +32,9 @@
       <artifactId>commons-collections</artifactId>
     </dependency>
     <dependency>
-      <groupId>org.jenkins-ci.dom4j</groupId>
+      <groupId>org.dom4j</groupId>
       <artifactId>dom4j</artifactId>
-      <version>1.6.1-jenkins-4</version>
+      <version>2.1.1</version>
     </dependency>
     <dependency><!-- only needed for annotations, hence optional -->
       <groupId>org.jvnet.maven-jellydoc-plugin</groupId>

does not work because of an API added to HtmlWriter used by Stapler's HTMLWriterOutput.

To be done:

• Write a unit test for HTMLWriterOutput demonstrating whatever it is supposed to do.
• Replace the missing setEnabled call. Perhaps just use Proxy to make a ContentHandler that dynamically switches between XMLWriter and HTMLWriter. That obviates the need for this patch. Close this PR accordingly.
• File an upstream PR for the static keyword addition from that patch.
• Update to 2.1.1 or newer. PR should link to this.
• File an upstream PR for this minor-looking improvement.
• Determine if this patch is even useful. If so, it can be done via the official getOmitElementCloseSet + setOmitElementCloseSet API.
• Forget about this patch since JENKINS-13709 is just one of many evil consequences of using maven-plugin.
• Recheck JENKINS-46616 which I think is not an issue in current library releases.

danielbeck is there some epic or label for issues proposing to switch from forked to official versions of libraries in Jenkins?

¹Using a different GA, no less. Noticed here: causes mayhem for plugins depending on the database plugin.