Merge REMERGE_HEAD into HEAD

changelog.html

@@ -55,6 +55,9 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
+  <li class=bug>
+    Fixed "java.lang.NoClassDefFoundError: JarURLConnection" on OpenJDK
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-20163">issue 20163</a>)
   <li class=bug>
     Allow background tasks to run simultaneously, preventing task blockage.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-19622">issue 19622</a>)

core/pom.xml

@@ -42,7 +42,7 @@ THE SOFTWARE.
 
   <properties>
     <staplerFork>true</staplerFork>
-    <stapler.version>1.222</stapler.version>
+    <stapler.version>1.223</stapler.version>
     <spring.version>2.5.6.SEC03</spring.version>
     <groovy.version>1.8.9</groovy.version>
   </properties>

core/src/main/java/jenkins/AgentProtocol.java

@@ -27,6 +27,10 @@ public abstract class AgentProtocol implements ExtensionPoint {
      * Protocol name.
      *
      * This is a short string that consists of printable ASCII chars. Sent by the client to select the protocol.
+     *
+     * @return
+     *      null to be disabled. This is useful for avoiding getting used
+     *      until the protocol is properly configured.
      */
     public abstract String getName();
 
@@ -44,7 +48,8 @@ public abstract class AgentProtocol implements ExtensionPoint {
 
     public static AgentProtocol of(String protocolName) {
         for (AgentProtocol p : all()) {
-            if (p.getName().equals(protocolName))
+            String n = p.getName();
+            if (n!=null && n.equals(protocolName))
                 return p;
         }
         return null;