[Fixed JENKINS-13129] Updating built-in plugins doesn't work, the file doesn't get pinned and is overwritten on the next startup

changed bundled plugin detection, added unit test

core/src/main/java/hudson/PluginManager.java

@@ -196,7 +196,7 @@ public abstract class PluginManager extends AbstractModelObject {
                                             PluginWrapper p = strategy.createPluginWrapper(arc);
                                             if (isDuplicate(p)) return;
 
-                                            p.isBundled = bundledPlugins.contains(arc.getName());
+                                            p.isBundled = containsHpiJpi(bundledPlugins, arc.getName());
                                             plugins.add(p);
                                         } catch (IOException e) {
                                             failedPlugins.add(new FailedPlugin(arc.getName(),e));
@@ -344,6 +344,15 @@ public abstract class PluginManager extends AbstractModelObject {
         }});
     }
 
+    /*
+     * contains operation that considers xxx.hpi and xxx.jpi as equal
+     * this is necessary since the bundled plugins are still called *.hpi 
+     */
+    private boolean containsHpiJpi(Collection<String> bundledPlugins, String name) {
+        return bundledPlugins.contains(name.replaceAll("\\.hpi",".jpi"))
+                || bundledPlugins.contains(name.replaceAll("\\.jpi",".hpi"));
+    }
+
     /**
      * TODO: revisit where/how to expose this. This is an experiment.
      */