Merge remote-tracking branch 'origin/master'

Conflicts:
	changelog.html

.gitignore

@@ -17,6 +17,9 @@ build
 # vim
 *~
 
+# ctags
+tags
+
 # OS X
 .DS_Store
 

changelog.html

@@ -54,9 +54,28 @@ Upcoming changes</a>
 
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
-<ul class=image>
-  <li class=>
-</ul>
+  <li class="rfe">
+    Plugin Manager UI changes to prevent users from enabling/disabling/uninstalling plugins at the "wrong" time.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-23150">issue 23150</a>)
+  <li class="bug">
+    bytecode-compatibility-transformer produces malformed bytecode.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-28781">issue 28781</a>)
+  <li class="bug">
+    Properly handle <code>RuntimeException</code>s in run retention policy handler calls.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-29888">issue 29888</a>)
+  <li class="bug">
+    Prevent <code>NullPointerException</code> in CLI if Jenkins cannot find the specified job
+    or a job with the nearest name.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-30742">issue 30742</a>)
+  <li class="bug">
+    Do not show <i>REST API</i> link for pages, which have no API handlers.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-29014">issue 29014</a>)
+  <li class="bug">
+    JS alert preventing to leave a configuration page without changes.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-21720">issue 21720</a>)
+  <li class="bug">
+    JS error triggered by collapsing build history widget.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-30569">issue 30569</a>)
 </div><!--=TRUNK-END=-->
 <h3><a name=v1.632>What's new in 1.632</a> (2015/10/05)</h3>
 <ul class=image>
@@ -72,6 +91,12 @@ Upcoming changes</a>
   <li class="rfe">
     ConsoleLogFilter wasn't truly global
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-30777">issue 30777</a>)
+  <li class="rfe">
+    API changes: <code>hudson.Util.isOverridden()</code> now supports protected methods.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-30002">issue 30002</a>)
+  <li class="bug">
+    Sidepanel controls with confirmation (<code>lib/layout/task</code>) did not assign the proper CSS style.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-30787">issue 30787</a>)
 </ul>
 <h3><a name=v1.631>What's new in 1.631</a> (2015/09/27)</h3>
 <ul class=image>

core/pom.xml

@@ -200,7 +200,7 @@ THE SOFTWARE.
     <dependency>
       <groupId>org.jenkins-ci</groupId>
       <artifactId>bytecode-compatibility-transformer</artifactId>
-      <version>1.5</version>
+      <version>1.6.2</version>
     </dependency>
     <dependency>
       <groupId>org.jenkins-ci</groupId>

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

@@ -119,6 +119,8 @@ import org.xml.sax.helpers.DefaultHandler;
 import static hudson.init.InitMilestone.*;
 import hudson.model.DownloadService;
 import hudson.util.FormValidation;
+
+import static java.util.logging.Level.SEVERE;
 import static java.util.logging.Level.WARNING;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
@@ -520,9 +522,33 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
             }
         }
 
+        // Redo who depends on who.
+        resolveDependantPlugins();
+
         LOGGER.info("Plugin " + p.getShortName()+":"+p.getVersion() + " dynamically installed");
     }
 
+    @Restricted(NoExternalUse.class)
+    public synchronized void resolveDependantPlugins() {
+        for (PluginWrapper plugin : plugins) {
+            Set<String> dependants = new HashSet<>();
+            for (PluginWrapper possibleDependant : plugins) {
+                // The plugin could have just been deleted. If so, it doesn't
+                // count as a dependant.
+                if (possibleDependant.isDeleted()) {
+                    continue;
+                }
+                List<Dependency> dependencies = possibleDependant.getDependencies();
+                for (Dependency dependency : dependencies) {
+                    if (dependency.shortName.equals(plugin.getShortName())) {
+                        dependants.add(possibleDependant.getShortName());
+                    }
+                }
+            }
+            plugin.setDependants(dependants);
+        }
+    }
+
     /**
      * If the war file has any "/WEB-INF/plugins/[*.jpi | *.hpi]", extract them into the plugin directory.
      *
@@ -779,6 +805,7 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
      */
     public void doInstall(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
         boolean dynamicLoad = req.getParameter("dynamicLoad")!=null;
+        final List<Future<UpdateCenter.UpdateCenterJob>> deployJobs = new ArrayList<>();
 
         Enumeration<String> en = req.getParameterNames();
         while (en.hasMoreElements()) {
@@ -811,9 +838,36 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
                 if (p == null) {
                     throw new Failure("No such plugin: " + n);
                 }
-                p.deploy(dynamicLoad);
+                
+                deployJobs.add(p.deploy(dynamicLoad));
             }
         }
+        
+        // Fire a one-off thread to wait for the plugins to be deployed and then
+        // refresh the dependant plugins list.
+        new Thread() {
+            @Override
+            public void run() {
+                INSTALLING: while (true) {
+                    for (Future<UpdateCenter.UpdateCenterJob> deployJob : deployJobs) {
+                        try {
+                            Thread.sleep(500);
+                        } catch (InterruptedException e) {
+                            LOGGER.log(SEVERE, "Unexpected error while waiting for some plugins to install. Plugin Manager state may be invalid. Please restart Jenkins ASAP.", e);
+                        }
+                        if (!deployJob.isCancelled() && !deployJob.isDone()) {
+                            // One of the plugins is not installing/canceled, so
+                            // go back to sleep and try again in a while.
+                            continue INSTALLING;
+                        }
+                    }
+                    // All the plugins are installed. It's now safe to refresh.
+                    resolveDependantPlugins();
+                    break;
+                }
+            }
+        }.start();
+        
         rsp.sendRedirect("../updateCenter/");
     }
 

core/src/main/java/hudson/PluginWrapper.java

@@ -24,6 +24,7 @@
  */
 package hudson;
 
+import com.google.common.collect.ImmutableSet;
 import hudson.PluginManager.PluginInstanceStore;
 import hudson.model.Api;
 import hudson.model.ModelObject;
@@ -40,7 +41,10 @@ import java.io.OutputStream;
 import java.io.Closeable;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 import java.util.jar.Manifest;
 import java.util.logging.Logger;
 import static java.util.logging.Level.WARNING;
@@ -57,6 +61,7 @@ import java.util.Enumeration;
 import java.util.jar.JarFile;
 import java.util.logging.Level;
 import javax.annotation.CheckForNull;
+import javax.annotation.Nonnull;
 
 /**
  * Represents a Jenkins plug-in and associated control information
@@ -150,6 +155,54 @@ public class PluginWrapper implements Comparable<PluginWrapper>, ModelObject {
      */
     /*package*/ boolean isBundled;
 
+    /**
+     * List of plugins that depend on this plugin.
+     */
+    private Set<String> dependants = Collections.emptySet();
+
+    /**
+     * The core can depend on a plugin if it is bundled. Sometimes it's the only thing that
+     * depends on the plugin e.g. UI support library bundle plugin.
+     */
+    private static Set<String> CORE_ONLY_DEPENDANT = ImmutableSet.copyOf(Arrays.asList("jenkins-core"));
+
+    /**
+     * Set the list of components that depend on this plugin.
+     * @param dependants The list of components that depend on this plugin.
+     */
+    public void setDependants(@Nonnull Set<String> dependants) {
+        this.dependants = dependants;
+    }
+
+    /**
+     * Get the list of components that depend on this plugin.
+     * @return The list of components that depend on this plugin.
+     */
+    public @Nonnull Set<String> getDependants() {
+        if (isBundled && dependants.isEmpty()) {
+            return CORE_ONLY_DEPENDANT;
+        } else {
+            return dependants;
+        }
+    }
+
+    /**
+     * Does this plugin have anything that depends on it.
+     * @return {@code true} if something (Jenkins core, or another plugin) depends on this
+     * plugin, otherwise {@code false}.
+     */
+    public boolean hasDependants() {
+        return (isBundled || !dependants.isEmpty());
+    }
+    
+    /**
+     * Does this plugin depend on any other plugins.
+     * @return {@code true} if this plugin depends on other plugins, otherwise {@code false}.
+     */
+    public boolean hasDependencies() {
+        return (dependencies != null && !dependencies.isEmpty());
+    }
+
     @ExportedBean
     public static final class Dependency {
         @Exported
@@ -632,8 +685,14 @@ public class PluginWrapper implements Comparable<PluginWrapper>, ModelObject {
 
     @RequirePOST
     public HttpResponse doDoUninstall() throws IOException {
-        Jenkins.getInstance().checkPermission(Jenkins.ADMINISTER);
+        Jenkins jenkins = Jenkins.getActiveInstance();
+        
+        jenkins.checkPermission(Jenkins.ADMINISTER);
         archive.delete();
+
+        // Redo who depends on who.
+        jenkins.getPluginManager().resolveDependantPlugins();
+
         return HttpResponses.redirectViaContextPath("/pluginManager/installed");   // send back to plugin manager
     }
 

core/src/main/java/hudson/Util.java

@@ -26,6 +26,7 @@ package hudson;
 import com.sun.jna.Memory;
 import com.sun.jna.Native;
 import com.sun.jna.NativeLong;
+
 import edu.umd.cs.findbugs.annotations.SuppressWarnings;
 import hudson.Proc.LocalProc;
 import hudson.model.TaskListener;
@@ -33,6 +34,7 @@ import hudson.os.PosixAPI;
 import hudson.util.QuotedStringTokenizer;
 import hudson.util.VariableResolver;
 import hudson.util.jna.WinIOException;
+
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.time.FastDateFormat;
 import org.apache.tools.ant.BuildException;
@@ -40,14 +42,18 @@ import org.apache.tools.ant.Project;
 import org.apache.tools.ant.taskdefs.Chmod;
 import org.apache.tools.ant.taskdefs.Copy;
 import org.apache.tools.ant.types.FileSet;
+
 import jnr.posix.FileStat;
 import jnr.posix.POSIX;
 
 import javax.crypto.SecretKey;
 import javax.crypto.spec.SecretKeySpec;
+
 import java.io.*;
 import java.lang.reflect.Array;
 import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
 import java.net.InetAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -70,12 +76,14 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import hudson.util.jna.Kernel32Utils;
-
 import static hudson.util.jna.GNUCLibrary.LIBC;
+
 import java.security.DigestInputStream;
+
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+
 import org.apache.commons.codec.digest.DigestUtils;
 
 /**
@@ -1415,16 +1423,36 @@ public class Util {
     }
 
     /**
-     * Checks if the public method defined on the base type with the given arguments
-     * are overridden in the given derived type.
+     * Checks if the method defined on the base type with the given arguments
+     * is overridden in the given derived type.
      */
     public static boolean isOverridden(@Nonnull Class base, @Nonnull Class derived, @Nonnull String methodName, @Nonnull Class... types) {
+        return !getMethod(base, methodName, types).equals(getMethod(derived, methodName, types));
+    }
+
+    private static Method getMethod(@Nonnull Class clazz, @Nonnull String methodName, @Nonnull Class... types) {
+        Method res = null;
         try {
-            return !base.getMethod(methodName, types).equals(
-                    derived.getMethod(methodName,types));
+            res = clazz.getDeclaredMethod(methodName, types);
+            // private, static or final methods can not be overridden
+            if (res != null && (Modifier.isPrivate(res.getModifiers()) || Modifier.isFinal(res.getModifiers()) 
+                    || Modifier.isStatic(res.getModifiers()))) {
+                res = null;
+            }
         } catch (NoSuchMethodException e) {
+            // Method not found in clazz, let's search in superclasses
+            Class superclass = clazz.getSuperclass();
+            if (superclass != null) {
+                res = getMethod(superclass, methodName, types);
+            }
+        } catch (SecurityException e) {
             throw new AssertionError(e);
         }
+        if (res == null) {
+            throw new IllegalArgumentException(
+                    String.format("Method %s not found in %s (or it is private, final or static)", methodName, clazz.getName()));
+        }
+        return res;
     }
 
     /**

core/src/main/java/hudson/model/AbstractProject.java

@@ -2248,8 +2248,11 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
     public static AbstractProject resolveForCLI(
             @Argument(required=true,metaVar="NAME",usage="Job name") String name) throws CmdLineException {
         AbstractProject item = Jenkins.getInstance().getItemByFullName(name, AbstractProject.class);
-        if (item==null)
-            throw new CmdLineException(null,Messages.AbstractItem_NoSuchJobExists(name,AbstractProject.findNearest(name).getFullName()));
+        if (item==null) {
+            AbstractProject project = AbstractProject.findNearest(name);
+            throw new CmdLineException(null, project == null ? Messages.AbstractItem_NoSuchJobExistsWithoutSuggestion(name)
+                    : Messages.AbstractItem_NoSuchJobExists(name, project.getFullName()));
+        }
         return item;
     }
 

core/src/main/java/hudson/model/Run.java

@@ -1803,11 +1803,9 @@ public abstract class Run <JobT extends Job<JobT,RunT>,RunT extends Run<JobT,Run
 
             try {
                 getParent().logRotate();
-            } catch (IOException e) {
-                LOGGER.log(Level.SEVERE, "Failed to rotate log",e);
-            } catch (InterruptedException e) {
-                LOGGER.log(Level.SEVERE, "Failed to rotate log",e);
-            }
+            } catch (Exception e) {
+		LOGGER.log(Level.SEVERE, "Failed to rotate log",e);
+	    }
         } finally {
             onEndBuilding();
         }

core/src/main/java/jenkins/model/Jenkins.java

@@ -864,6 +864,9 @@ public class Jenkins extends AbstractCIBase implements DirectlyModifiableTopLeve
                             System.currentTimeMillis()-itemListenerStart,l.getClass().getName()));
             }
 
+            // All plugins are loaded. Now we can figure out who depends on who.
+            resolveDependantPlugins();
+
             if (LOG_STARTUP_PERFORMANCE)
                 LOGGER.info(String.format("Took %dms for complete Jenkins startup",
                         System.currentTimeMillis()-start));
@@ -872,6 +875,19 @@ public class Jenkins extends AbstractCIBase implements DirectlyModifiableTopLeve
         }
     }
 
+    private void resolveDependantPlugins() throws InterruptedException, ReactorException, IOException {
+        TaskGraphBuilder graphBuilder = new TaskGraphBuilder();
+
+        graphBuilder.add("Resolving Dependant Plugins Graph", new Executable() {
+            @Override
+            public void run(Reactor reactor) throws Exception {
+                pluginManager.resolveDependantPlugins();
+            }
+        });
+
+        executeReactor(null, graphBuilder);
+    }
+
     /**
      * Executes a reactor.
      *

core/src/main/resources/hudson/PluginManager/_table.js

@@ -44,3 +44,351 @@ Behaviour.specify("#filter-box", '_table', 0, function(e) {
 
       e.onkeyup = applyFilter;
 });
+
+/**
+ * Code for handling the enable/disable behavior based on plugin
+ * dependencies and dependants.
+ */
+(function(){
+    function selectAll(selector, element) {
+        if (element) {
+            return $(element).select(selector);
+        } else {
+            return Element.select(undefined, selector);
+        }
+    }
+    function select(selector, element) {
+        var elementsBySelector = selectAll(selector, element);
+        if (elementsBySelector.length > 0) {
+            return  elementsBySelector[0];
+        } else {
+            return undefined;
+        }
+    }
+
+    /**
+     * Wait for document onload.
+     */    
+    Element.observe(window, "load", function() {        
+        var pluginsTable = select('#plugins');
+        var pluginTRs = selectAll('.plugin', pluginsTable);
+        
+        if (!pluginTRs) {
+            return;
+        }
+
+        var pluginI18n = select('.plugins.i18n');
+        function i18n(messageId) {
+            return pluginI18n.getAttribute('data-' + messageId);
+        }
+        
+        // Create a map of the plugin rows, making it easy to index them.
+        var plugins = {};
+        for (var i = 0; i < pluginTRs.length; i++) {
+            var pluginTR = pluginTRs[i];
+            var pluginId = pluginTR.getAttribute('data-plugin-id');
+            
+            plugins[pluginId] = pluginTR;
+        }
+        
+        function getPluginTR(pluginId) {
+            return plugins[pluginId];
+        }
+        function getPluginName(pluginId) {
+            var pluginTR = getPluginTR(pluginId);
+            if (pluginTR) {
+                return pluginTR.getAttribute('data-plugin-name');
+            } else {
+                return pluginId;
+            }
+        }
+        
+        function processSpanSet(spans) {
+            var ids = [];
+            for (var i = 0; i < spans.length; i++) {
+                var span = spans[i];
+                var pluginId = span.getAttribute('data-plugin-id');
+                var pluginName = getPluginName(pluginId);
+                
+                span.update(pluginName);
+                ids.push(pluginId);
+            }
+            return ids;
+        }
+        
+        function markAllDependantsDisabled(pluginTR) {
+            var jenkinsPluginMetadata = pluginTR.jenkinsPluginMetadata;
+            var dependantIds = jenkinsPluginMetadata.dependantIds;
+            
+            if (dependantIds) {
+                // If the only dependant is jenkins-core (it's a bundle plugin), then lets
+                // treat it like all its dependants are disabled. We're really only interested in
+                // dependant plugins in this case.
+                // Note: This does not cover "implied" dependencies ala detached plugins. See https://goo.gl/lQHrUh
+                if (dependantIds.length === 1 && dependantIds[0] === 'jenkins-core') {
+                    pluginTR.addClassName('all-dependants-disabled');
+                    return;
+                }
+
+                for (var i = 0; i < dependantIds.length; i++) {
+                    var dependantId = dependantIds[i];
+
+                    if (dependantId === 'jenkins-core') {
+                        // Jenkins core is always enabled. So, make sure it's not possible to disable/uninstall
+                        // any plugins that it "depends" on. (we sill have bundled plugins)
+                        pluginTR.removeClassName('all-dependants-disabled');
+                        return;
+                    }
+                    
+                    // The dependant is a plugin....
+                    var dependantPluginTr = getPluginTR(dependantId);
+                    if (dependantPluginTr && dependantPluginTr.jenkinsPluginMetadata.enableInput.checked) {
+                        // One of the plugins that depend on this plugin, is marked as enabled.
+                        pluginTR.removeClassName('all-dependants-disabled');
+                        return;
+                    }
+                }
+            }
+            
+            pluginTR.addClassName('all-dependants-disabled');
+        }
+
+        function markHasDisabledDependencies(pluginTR) {
+            var jenkinsPluginMetadata = pluginTR.jenkinsPluginMetadata;
+            var dependencyIds = jenkinsPluginMetadata.dependencyIds;
+            
+            if (dependencyIds) {
+                for (var i = 0; i < dependencyIds.length; i++) {
+                    var dependencyPluginTr = getPluginTR(dependencyIds[i]);
+                    if (dependencyPluginTr && !dependencyPluginTr.jenkinsPluginMetadata.enableInput.checked) {
+                        // One of the plugins that this plugin depend on, is marked as disabled.
+                        pluginTR.addClassName('has-disabled-dependency');
+                        return;
+                    }
+                }
+            }
+            
+            pluginTR.removeClassName('has-disabled-dependency');
+        }
+        
+        function setEnableWidgetStates() {
+            for (var i = 0; i < pluginTRs.length; i++) {
+                markAllDependantsDisabled(pluginTRs[i]);
+                markHasDisabledDependencies(pluginTRs[i]);
+            }
+        }
+        
+        function addDependencyInfoRow(pluginTR, infoTR) {
+            infoTR.addClassName('plugin-dependency-info');
+            pluginTR.insert({
+                after: infoTR
+            });
+        }
+        function removeDependencyInfoRow(pluginTR) {
+            var nextRows = pluginTR.nextSiblings();
+            if (nextRows && nextRows.length > 0) {
+                var nextRow = nextRows[0];
+                if (nextRow.hasClassName('plugin-dependency-info')) {
+                    nextRow.remove();
+                }
+            }
+        }
+
+        function populateEnableDisableInfo(pluginTR, infoContainer) {    
+            var pluginMetadata = pluginTR.jenkinsPluginMetadata;
+
+            // Remove all existing class info
+            infoContainer.removeAttribute('class');
+            infoContainer.addClassName('enable-state-info');
+
+            if (pluginTR.hasClassName('has-disabled-dependency')) {
+                var dependenciesDiv = pluginMetadata.dependenciesDiv;
+                var dependencySpans = pluginMetadata.dependencies;
+
+                infoContainer.update('<div class="title">' + i18n('cannot-enable') + '</div><div class="subtitle">' + i18n('disabled-dependencies') + '.</div>');
+                
+                // Go through each dependency <span> element. Show the spans where the dependency is
+                // disabled. Hide the others. 
+                for (var i = 0; i < dependencySpans.length; i++) {
+                    var dependencySpan = dependencySpans[i];
+                    var pluginId = dependencySpan.getAttribute('data-plugin-id');
+                    var depPluginTR = getPluginTR(pluginId);
+                    var depPluginMetadata = depPluginTR.jenkinsPluginMetadata;
+                    if (depPluginMetadata.enableInput.checked) {
+                        // It's enabled ... hide the span
+                        dependencySpan.setStyle({display: 'none'});
+                    } else {
+                        // It's disabled ... show the span
+                        dependencySpan.setStyle({display: 'inline-block'});
+                    }
+                }
+                
+                dependenciesDiv.setStyle({display: 'inherit'});
+                infoContainer.appendChild(dependenciesDiv);
+                
+                return true;
+            } if (pluginTR.hasClassName('has-dependants')) {
+                if (!pluginTR.hasClassName('all-dependants-disabled')) {
+                    var dependantIds = pluginMetadata.dependantIds;
+                    
+                    // If the only dependant is jenkins-core (it's a bundle plugin), then lets
+                    // treat it like all its dependants are disabled. We're really only interested in
+                    // dependant plugins in this case.
+                    // Note: This does not cover "implied" dependencies ala detached plugins. See https://goo.gl/lQHrUh
+                    if (dependantIds.length === 1 && dependantIds[0] === 'jenkins-core') {
+                        pluginTR.addClassName('all-dependants-disabled');
+                        return false;
+                    }
+                    
+                    var dependantsDiv = pluginMetadata.dependantsDiv;
+                    var dependantSpans = pluginMetadata.dependants;
+
+                    infoContainer.update('<div class="title">' + i18n('cannot-disable') + '</div><div class="subtitle">' + i18n('enabled-dependants') + '.</div>');
+                    
+                    // Go through each dependant <span> element. Show the spans where the dependant is
+                    // enabled. Hide the others. 
+                    for (var i = 0; i < dependantSpans.length; i++) {
+                        var dependantSpan = dependantSpans[i];
+                        var dependantId = dependantSpan.getAttribute('data-plugin-id');
+                        
+                        if (dependantId === 'jenkins-core') {
+                            // show the span
+                            dependantSpan.setStyle({display: 'inline-block'});
+                        } else {
+                            var depPluginTR = getPluginTR(dependantId);
+                            var depPluginMetadata = depPluginTR.jenkinsPluginMetadata;
+                            if (depPluginMetadata.enableInput.checked) {
+                                // It's enabled ... show the span
+                                dependantSpan.setStyle({display: 'inline-block'});
+                            } else {
+                                // It's disabled ... hide the span
+                                dependantSpan.setStyle({display: 'none'});
+                            }
+                        }
+                    }
+                    
+                    dependantsDiv.setStyle({display: 'inherit'});
+                    infoContainer.appendChild(dependantsDiv);
+
+                    return true;
+                }
+            }
+            
+            return false;
+        }
+
+        function populateUninstallInfo(pluginTR, infoContainer) {
+            // Remove all existing class info
+            infoContainer.removeAttribute('class');
+            infoContainer.addClassName('uninstall-state-info');
+
+            if (pluginTR.hasClassName('has-dependants')) {
+                var pluginMetadata = pluginTR.jenkinsPluginMetadata;
+                var dependantsDiv = pluginMetadata.dependantsDiv;
+                var dependantSpans = pluginMetadata.dependants;
+
+                infoContainer.update('<div class="title">' + i18n('cannot-uninstall') + '</div><div class="subtitle">' + i18n('installed-dependants') + '.</div>');
+                
+                // Go through each dependant <span> element. Show them all. 
+                for (var i = 0; i < dependantSpans.length; i++) {
+                    var dependantSpan = dependantSpans[i];
+                    dependantSpan.setStyle({display: 'inline-block'});
+                }
+                
+                dependantsDiv.setStyle({display: 'inherit'});
+                infoContainer.appendChild(dependantsDiv);
+                
+                return true;
+            }
+            
+            return false;
+        }
+
+        function initPluginRowHandling(pluginTR) {
+            var enableInput = select('.enable input', pluginTR);
+            var dependenciesDiv = select('.dependency-list', pluginTR);
+            var dependantsDiv = select('.dependant-list', pluginTR);
+            var enableTD = select('td.enable', pluginTR);
+            var uninstallTD = select('td.uninstall', pluginTR);
+            
+            pluginTR.jenkinsPluginMetadata = {
+                enableInput: enableInput,
+                dependenciesDiv: dependenciesDiv,
+                dependantsDiv: dependantsDiv
+            };
+
+            if (dependenciesDiv) {
+                pluginTR.jenkinsPluginMetadata.dependencies = selectAll('span', dependenciesDiv);
+                pluginTR.jenkinsPluginMetadata.dependencyIds = processSpanSet(pluginTR.jenkinsPluginMetadata.dependencies);
+            }
+            if (dependantsDiv) {
+                pluginTR.jenkinsPluginMetadata.dependants = selectAll('span', dependantsDiv);
+                pluginTR.jenkinsPluginMetadata.dependantIds = processSpanSet(pluginTR.jenkinsPluginMetadata.dependants);
+            }
+            
+            // Setup event handlers...
+            
+            // Toggling of the enable/disable checkbox requires a check and possible
+            // change of visibility on the same checkbox on other plugins.
+            Element.observe(enableInput, 'click', function() {
+                setEnableWidgetStates();
+            });
+            
+            // 
+            var infoTR = document.createElement("tr");
+            var infoTD = document.createElement("td");
+            var infoDiv = document.createElement("div");
+            infoTR.appendChild(infoTD)
+            infoTD.appendChild(infoDiv)
+            infoTD.setAttribute('colspan', '6'); // This is the cell that all info will be added to.
+            infoDiv.setStyle({display: 'inherit'});
+
+            // We don't want the info row to appear immediately. We wait for e.g. 1 second and if the mouse
+            // is still in there (hasn't left the cell) then we show. The following code is for clearing the
+            // show timeout where the mouse has left before the timeout has fired.
+            var showInfoTimeout = undefined;
+            function clearShowInfoTimeout() {
+                if (showInfoTimeout) {
+                    clearTimeout(showInfoTimeout);
+                }
+                showInfoTimeout = undefined;
+            }
+            
+            // Handle mouse in/out of the enable/disable cell (left most cell).
+            Element.observe(enableTD, 'mouseenter', function() {
+                showInfoTimeout = setTimeout(function() {
+                    showInfoTimeout = undefined;
+                    infoDiv.update('');
+                    if (populateEnableDisableInfo(pluginTR, infoDiv)) {
+                        addDependencyInfoRow(pluginTR, infoTR);
+                    }
+                }, 1000);
+            });
+            Element.observe(enableTD, 'mouseleave', function() {
+                clearShowInfoTimeout();
+                removeDependencyInfoRow(pluginTR);
+            });
+
+            // Handle mouse in/out of the uninstall cell (right most cell).
+            Element.observe(uninstallTD, 'mouseenter', function() {
+                showInfoTimeout = setTimeout(function() {
+                    showInfoTimeout = undefined;
+                    infoDiv.update('');
+                    if (populateUninstallInfo(pluginTR, infoDiv)) {
+                        addDependencyInfoRow(pluginTR, infoTR);
+                    }
+                }, 1000);
+            });
+            Element.observe(uninstallTD, 'mouseleave', function() {
+                clearShowInfoTimeout();
+                removeDependencyInfoRow(pluginTR);
+            });
+        }
+
+        for (var i = 0; i < pluginTRs.length; i++) {
+            initPluginRowHandling(pluginTRs[i]);
+        }
+        
+        setEnableWidgetStates();
+    });
+}());
\ No newline at end of file

core/src/main/resources/hudson/PluginManager/installed.jelly

@@ -35,10 +35,23 @@ THE SOFTWARE.
             ${%Filter}:
             <input type="text" id="filter-box"/>
         </div>
+
+      <j:if test="${app.updateCenter.isRestartRequiredForCompletion()}">
+        <div class="alert alert-warning"><strong>${%Warning}</strong>: ${%requires.restart}</div>
+      </j:if>
+        
       <local:tabBar page="installed" xmlns:local="/hudson/PluginManager" />
 
       <div class="pane-frame">
-        <table id="plugins" class="sortable pane bigtable stripped-odd">
+        <div class="plugins i18n" 
+             data-cannot-enable="${%This plugin cannot be enabled}" 
+             data-cannot-disable="${%This plugin cannot be disabled}" 
+             data-cannot-uninstall="${%This plugin cannot be uninstalled}" 
+             data-disabled-dependencies="${%It has one or more disabled dependencies}" 
+             data-enabled-dependants="${%It has one or more enabled dependants}" 
+             data-installed-dependants="${%It has one or more installed dependants}" 
+        />
+        <table id="plugins" class="pane bigtable sortable stripped-odd">
           <j:choose>
             <j:when test="${empty(app.pluginManager.plugins) and empty(app.pluginManager.failedPlugins)}">
               <tr><td>
@@ -55,16 +68,16 @@ THE SOFTWARE.
                 <th width="1">${%Uninstall}</th>
               </tr>
               <j:forEach var="p" items="${app.pluginManager.plugins}">
-                <tr class="plugin">
+                <tr class="plugin ${p.hasDependants()?'has-dependants':''} ${p.isDeleted()?'deleted':''}" data-plugin-id="${p.shortName}" data-plugin-name="${p.displayName}">
                   <j:set var="state" value="${p.enabled?'true':null}"/>
-                  <td class="center pane" data="${state}">
+                  <td class="center pane enable" data="${state}">
                     <input type="checkbox" checked="${state}" onclick="flip(event)"
                            url="plugin/${p.shortName}"
                            original="${p.active?'true':'false'}"/>
                   </td>
-                  <td class="pane">
+                  <td class="pane details">
                     <div>
-                      <a href="${p.url}">
+                      <a href="${p.url}" class="display-name">
                         ${p.updateInfo.displayName?:p.displayName}
                       </a>
                     </div>
@@ -106,16 +119,30 @@ THE SOFTWARE.
                       <a href="${%wiki.url}" target="_blank"><l:icon class="icon-help icon-sm" style="vertical-align:top"/></a>
                     </j:if>
                   </td>
-                  <td class="center pane">
+                  <td class="center pane uninstall">
                     <j:choose>
                       <j:when test="${p.isDeleted()}">
                         <p>${%Uninstallation pending}</p>
                       </j:when>
-                      <j:when test="${!p.isBundled()}">
-                        <form method="post" action="plugin/${p.shortName}/uninstall">
-                          <input type="submit" value="${%Uninstall}"/>
-                        </form>
-                      </j:when>
+                      <j:otherwise>
+                          <j:if test="${p.hasDependants()}">
+                            <div class="dependant-list">
+                              <j:forEach var="dependant" items="${p.dependants}">
+                                <span data-plugin-id="${dependant}"></span>
+                              </j:forEach>
+                            </div>
+                          </j:if>
+                          <j:if test="${p.hasDependencies()}">
+                            <div class="dependency-list">
+                              <j:forEach var="dependency" items="${p.dependencies}">
+                                <span data-plugin-id="${dependency.shortName}"></span>  
+                              </j:forEach>
+                            </div>
+                          </j:if>
+                          <form method="post" action="plugin/${p.shortName}/uninstall">
+                              <input class="uninstall" type="submit" value="${%Uninstall}"/>
+                          </form>
+                      </j:otherwise>
                     </j:choose>
                   </td>
                 </tr>

core/src/main/resources/hudson/PluginManager/installed.properties

@@ -20,4 +20,5 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 wiki.url=http://wiki.jenkins-ci.org/display/JENKINS/Pinned+Plugins
-downgradeTo=Downgrade to {0}
\ No newline at end of file
+downgradeTo=Downgrade to {0}
+requires.restart=This Jenkins instance requires a restart. Changing the state of plugins at this time is strongly discouraged. Restart Jenkins before proceeding.
\ No newline at end of file

core/src/main/resources/hudson/widgets/HistoryWidget/index.jelly

@@ -101,7 +101,9 @@ THE SOFTWARE.
       </tr>
     </j:if>
   </l:pane>
-  <script defer="true">
-    updateBuildHistory("${it.baseUrl}/buildHistory/ajax",${it.nextBuildNumberToFetch});
-  </script>
+  <j:if test="!empty(it.nextBuildNumberToFetch)">
+    <script defer="true">
+      updateBuildHistory("${it.baseUrl}/buildHistory/ajax", ${it.nextBuildNumberToFetch});
+    </script>
+  </j:if>
 </j:jelly>

core/src/main/resources/lib/form/confirm.js

@@ -33,9 +33,6 @@
     }
 
     function initConfirm() {
-      // Timeout is needed since some events get sent on page load for some reason.
-      // Shouldn't hurt anything for this to only start monitoring events after a few millis;.
-      setTimeout(function() {
       var configForm = document.getElementsByName("config");
       if (configForm.length > 0) {
         configForm = configForm[0]
@@ -78,7 +75,6 @@
       for ( var i = 0; i < inputs.length; i++) {
         $(inputs[i]).on('input', confirm);
       }
-      }, 100);
     }
 
     window.onbeforeunload = confirmExit;

core/src/main/resources/lib/form/select/select.js

@@ -41,6 +41,19 @@ function updateListBox(listBox,url,config) {
 }
 
 Behaviour.specify("SELECT.select", 'select', 1000, function(e) {
+
+        function hasChanged(selectEl, originalValue) {
+            var firstValue = selectEl.options[0].value;
+            var selectedValue = selectEl.value;
+            if (originalValue == "" && selectedValue == firstValue) {
+                // There was no value pre-selected but after the call to updateListBox the first value is selected by
+                // default. This must not be considered a change.
+                return false;
+            } else {
+                return originalValue != selectedValue;
+            }
+        };
+
         // controls that this SELECT box depends on
         refillOnChange(e,function(params) {
             var value = e.value;
@@ -60,7 +73,9 @@ Behaviour.specify("SELECT.select", 'select', 1000, function(e) {
                     fireEvent(e,"filled"); // let other interested parties know that the items have changed
 
                     // if the update changed the current selection, others listening to this control needs to be notified.
-                    if (e.value!=value) fireEvent(e,"change");
+                    if (hasChanged(e, value)) {
+                        fireEvent(e,"change");
+                    }
                 }
             });
         });

core/src/main/resources/lib/layout/layout.jelly

@@ -254,7 +254,9 @@ ${h.initPageVariables(context)}
           <div class="col-md-6" id="footer"></div>
           <div class="col-md-18">
             <span class="page_generated">${%Page generated}: <i:formatDate value="${h.getCurrentTime()}" type="both" dateStyle="medium" timeStyle="medium"/></span>
-            <span class="rest_api"><a href="api/">REST API</a></span>
+            <j:if test="${!empty(it.api)}">
+               <span class="rest_api"><a href="api/">REST API</a></span>
+            </j:if>
             <span class="jenkins_ver"><a href="${h.getFooterURL()}">Jenkins ver. ${h.version}</a></span>
             <j:if test="${extensionsAvailable}">
             <j:forEach var="pd" items="${h.pageDecorators}">

core/src/main/resources/lib/layout/task.jelly

@@ -167,7 +167,7 @@ THE SOFTWARE.
 
           <j:choose>
             <j:when test="${requiresConfirmation and not attrs.onClick}">
-              <l:confirmationLink href="${href}" post="${post}" message="${confirmationMessage ?: title}">
+              <l:confirmationLink class="task-icon-link" href="${href}" post="${post}" message="${confirmationMessage ?: title}">
                 <j:choose>
                   <j:when test="${iconMetadata != null}">
                     <l:icon class="${iconMetadata.classSpec}" style="width: 24px; height: 24px; margin: 2px;" />

core/src/test/java/hudson/util/IsOverriddenTest.java

+/*
+ * The MIT License
+ *
+ * Copyright (c) 2015, CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package hudson.util;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+import hudson.Util;
+
+/**
+ * Test for {@link Util.isOverridden} method.
+ */
+public class IsOverriddenTest {
+
+    /**
+     * Test that a method is found by isOverridden even when it is inherited from an intermediate class.
+     */
+    @Test
+    public void isOverriddenTest() {
+        assertTrue(Util.isOverridden(Base.class, Derived.class, "method"));
+        assertTrue(Util.isOverridden(Base.class, Intermediate.class, "method"));
+        assertFalse(Util.isOverridden(Base.class, Base.class, "method"));
+        assertTrue(Util.isOverridden(Base.class, Intermediate.class, "setX", Object.class));
+        assertTrue(Util.isOverridden(Base.class, Intermediate.class, "getX"));
+    }
+
+    /**
+     * Negative test.
+     * Trying to check for a method which does not exist in the hierarchy,
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void isOverriddenNegativeTest() {
+        Util.isOverridden(Base.class, Derived.class, "method2");
+    }
+
+    /**
+     * Do not inspect private methods.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void avoidPrivateMethodsInspection() {
+        Util.isOverridden(Base.class, Intermediate.class, "aPrivateMethod");
+    }
+
+    public abstract class Base<T> {
+        protected abstract void method();
+        private void aPrivateMethod() {}
+        public void setX(T t) {}
+        public T getX() { return null; }
+    }
+    public abstract class Intermediate extends Base<Integer> {
+        protected void method() {}
+        private void aPrivateMethod() {}
+        public void setX(Integer i) {}
+        public Integer getX() { return 0; }
+    }
+    public class Derived extends Intermediate {}
+
+}
+

test/src/test/groovy/hudson/model/AbstractProjectTest.groovy

@@ -47,7 +47,8 @@ import hudson.triggers.Trigger
 import hudson.triggers.TriggerDescriptor;
 import hudson.util.StreamTaskListener;
 import hudson.util.OneShotEvent
-import jenkins.model.Jenkins;
+import jenkins.model.Jenkins
+import org.junit.Assert;
 import org.jvnet.hudson.test.HudsonTestCase
 import org.jvnet.hudson.test.Issue;
 import org.jvnet.hudson.test.TestExtension;
@@ -56,6 +57,7 @@ import org.jvnet.hudson.test.recipes.PresetData.DataSet
 import org.apache.commons.io.FileUtils;
 import org.junit.Assume;
 import org.jvnet.hudson.test.MockFolder
+import org.kohsuke.args4j.CmdLineException
 
 /**
  * @author Kohsuke Kawaguchi
@@ -588,6 +590,25 @@ public class AbstractProjectTest extends HudsonTestCase {
         assert project.triggers().size() == 1
     }
 
+    @Issue("JENKINS-30742")
+    public void testResolveForCLI() {
+        try {
+            AbstractProject not_found = AbstractProject.resolveForCLI("never_created");
+            fail("Exception should occur before!");
+        } catch (CmdLineException e) {
+            assert e.getMessage().contentEquals("No such job \u2018never_created\u2019 exists.");
+        }
+
+        AbstractProject project = jenkins.createProject(FreeStyleProject.class, "never_created");
+        try {
+            AbstractProject not_found = AbstractProject.resolveForCLI("never_created1");
+            fail("Exception should occur before!");
+        } catch (CmdLineException e) {
+            assert e.getMessage().contentEquals("No such job \u2018never_created1\u2019 exists. Perhaps you meant \u2018never_created\u2019?")
+        }
+
+    }
+
     static class MockBuildTriggerThrowsNPEOnStart<Item> extends Trigger {
         @Override
         public void start(hudson.model.Item project, boolean newInstance) { throw new NullPointerException(); }

test/src/test/java/hudson/PluginManagerInstalledGUITest.java

+/*
+ * The MIT License
+ *
+ * Copyright (c) 2015, CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package hudson;
+
+import com.gargoylesoftware.htmlunit.html.DomElement;
+import com.gargoylesoftware.htmlunit.html.HtmlElement;
+import com.gargoylesoftware.htmlunit.html.HtmlElementUtil;
+import com.gargoylesoftware.htmlunit.html.HtmlInput;
+import com.gargoylesoftware.htmlunit.html.HtmlPage;
+import com.gargoylesoftware.htmlunit.html.HtmlTableRow;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.recipes.WithPlugin;
+import org.xml.sax.SAXException;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * @author <a href="mailto:tom.fennelly@gmail.com">tom.fennelly@gmail.com</a>
+ */
+public class PluginManagerInstalledGUITest {
+
+    @Rule
+    public JenkinsRule jenkinsRule = new JenkinsRule();
+    
+    @Test
+    @WithPlugin("tasks.jpi")
+    public void test_enable_disable_uninstall() throws IOException, SAXException {
+        InstalledPlugins installedPlugins = new InstalledPlugins();
+        
+        InstalledPlugin tasksPlugin = installedPlugins.get("tasks");
+        InstalledPlugin cvsPlugin = installedPlugins.get("cvs");
+
+        tasksPlugin.assertHasNoDependants();
+        cvsPlugin.assertHasDependants();
+        
+        // Tasks plugin should be enabled and it should be possible to disable it
+        // because no other plugins depend on it.
+        tasksPlugin.assertEnabled();
+        tasksPlugin.assertEnabledStateChangeable();
+        tasksPlugin.assertUninstallable();
+        
+        // CVS plugin should be enabled, but it should not be possible to disable or uninstall it
+        // because the tasks plugin depends on it.
+        cvsPlugin.assertEnabled();
+        cvsPlugin.assertEnabledStateNotChangeable();
+        cvsPlugin.assertNotUninstallable();
+        
+        // Disable the tasks plugin
+        tasksPlugin.clickEnabledWidget();
+                
+        // Now the tasks plugin should be disabled, but it should be possible to re-enable it 
+        // and it should still be uninstallable.
+        tasksPlugin.assertNotEnabled(); // this is different to earlier
+        tasksPlugin.assertEnabledStateChangeable();
+        tasksPlugin.assertUninstallable();
+                
+        // The CVS plugin should still be enabled, but it should now be possible to disable it because
+        // the tasks plugin is no longer enabled. Should still not be possible to uninstall it.
+        cvsPlugin.assertEnabled();
+        cvsPlugin.assertEnabledStateChangeable(); // this is different to earlier
+        cvsPlugin.assertNotUninstallable();
+        
+        // Disable the cvs plugin
+        cvsPlugin.clickEnabledWidget();
+        
+        // Now it should NOT be possible to change the enable state of the tasks plugin because one
+        // of the plugins it depends on (the CVS plugin) is not enabled.
+        tasksPlugin.assertNotEnabled();
+        tasksPlugin.assertEnabledStateNotChangeable();  // this is different to earlier
+        tasksPlugin.assertUninstallable();
+    }
+    
+    private class InstalledPlugins {
+        
+        private final List<InstalledPlugin> installedPlugins;
+
+        private InstalledPlugins () throws IOException, SAXException {
+            JenkinsRule.WebClient webClient = jenkinsRule.createWebClient();
+            HtmlPage installedPage = webClient.goTo("pluginManager/installed");
+            
+            // Note for debugging... simply print installedPage to get the JenkinsRule
+            // Jenkins URL and then add a long Thread.sleep here. It's useful re being
+            // able to see what the code is testing.
+
+            DomElement pluginsTable = installedPage.getElementById("plugins");
+            HtmlElement tbody = pluginsTable.getElementsByTagName("TBODY").get(0);
+            
+            installedPlugins = new ArrayList<>();
+            for (DomElement htmlTableRow : tbody.getChildElements()) {
+                installedPlugins.add(new InstalledPlugin((HtmlTableRow) htmlTableRow));
+            }
+        }
+
+        public InstalledPlugin get(String pluginId) {
+            for (InstalledPlugin plugin : installedPlugins) {
+                if (plugin.isPlugin(pluginId)) {
+                    return plugin;
+                }
+            }
+            Assert.fail("Now pluginManager/installed row for plugin " + pluginId);
+            return null;
+        }
+
+    }
+
+    private class InstalledPlugin {
+
+        private final HtmlTableRow pluginRow;
+
+        public InstalledPlugin(HtmlTableRow pluginRow) {
+            this.pluginRow = pluginRow;
+        }
+        
+        public String getId() {
+            return pluginRow.getAttribute("data-plugin-id");
+        }
+        
+        public boolean isPlugin(String pluginId) {
+            return pluginId.equals(getId());
+        }
+        
+        private HtmlInput getEnableWidget() {
+            HtmlElement input = pluginRow.getCells().get(0).getElementsByTagName("input").get(0);
+            return (HtmlInput) input;
+        }
+
+        public void assertEnabled() {
+            HtmlInput enableWidget = getEnableWidget();
+            Assert.assertTrue("Plugin '" + getId() + "' is expected to be enabled.", enableWidget.isChecked());
+        }
+
+        public void assertNotEnabled() {
+            HtmlInput enableWidget = getEnableWidget();
+            Assert.assertFalse("Plugin '" + getId() + "' is not expected to be enabled.", enableWidget.isChecked());
+        }
+
+        public void clickEnabledWidget() throws IOException {
+            HtmlInput enableWidget = getEnableWidget();
+            HtmlElementUtil.click(enableWidget);
+        }
+
+        public void assertEnabledStateChangeable() {
+            if (!hasDependants() && !hasDisabledDependency() && !allDependantsDisabled()) {
+                return;
+            }
+            if (allDependantsDisabled() && !hasDisabledDependency()) {
+                return;
+            }
+            
+            Assert.fail("The enable/disable state of plugin '" + getId() + "' cannot be changed.");
+        }
+
+        public void assertEnabledStateNotChangeable() {
+            if (hasDependants() && !hasDisabledDependency() && !allDependantsDisabled()) {
+                return;
+            }
+            if (!hasDependants() && hasDisabledDependency()) {
+                return;
+            }
+            
+            Assert.fail("The enable/disable state of plugin '" + getId() + "' cannot be changed.");
+        }
+
+        public void assertUninstallable() {
+            Assert.assertFalse("Plugin '" + getId() + "' cannot be uninstalled.", hasDependants());
+        }
+
+        public void assertNotUninstallable() {
+            Assert.assertTrue("Plugin '" + getId() + "' can be uninstalled.", hasDependants());
+        }
+
+        public void assertHasDependants() {
+            Assert.assertTrue(hasDependants());
+        }
+
+        public void assertHasNoDependants() {
+            Assert.assertFalse(hasDependants());
+        }
+
+        private boolean hasClassName(String className) {
+            String classAttribute = pluginRow.getAttribute("class");
+            Set<String> classes = new HashSet<>(Arrays.asList(classAttribute.split(" ")));
+            return classes.contains(className);
+        }
+
+        private boolean hasDisabledDependency() {
+            return hasClassName("has-disabled-dependency");
+        }
+
+        private boolean allDependantsDisabled() {
+            return hasClassName("all-dependants-disabled");
+        }
+
+        private boolean hasDependants() {
+            return hasClassName("has-dependants");
+        }
+    }
+}

test/src/test/java/hudson/slaves/CommandLauncherTest.java

@@ -26,7 +26,6 @@ package hudson.slaves;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.not;
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
@@ -40,6 +39,7 @@ import java.util.concurrent.TimeUnit;
 import org.junit.Rule;
 import org.junit.Test;
 import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.RandomlyFails;
 
 public class CommandLauncherTest {
 
@@ -57,8 +57,9 @@ public class CommandLauncherTest {
         assertThat(log, not(containsString("ERROR: Process terminated with exit code 0")));
     }
 
+    @RandomlyFails("Sometimes gets `EOFException: unexpected stream termination` before then on CI builder; maybe needs to wait in a loop for a message to appear?")
     @Test
-    public void commandSuceedsWithoutChannel() throws Exception {
+    public void commandSucceedsWithoutChannel() throws Exception {
         assumeTrue(!Functions.isWindows());
         DumbSlave slave = createSlave("true");
 

war/src/main/webapp/css/style.css

@@ -1221,6 +1221,86 @@ TABLE.fingerprint-in-build TD {
   background-color: #e8eeee;
 }
 
+#plugins input.uninstall {
+  font-size: 11px;
+  padding: 3px 5px;
+  border-radius: 1px;
+  font-family: Helvetica, Arial, sans-serif;
+  font-weight: bold;
+  background-color: #4b758b;
+  color: #eee;
+  border: 1px solid #5788a1;
+}
+
+#plugins tr.has-dependants input.uninstall {
+  background-color: #e0e0e0;
+  border: 1px solid #cccccc;
+  color: #505050;
+  background-color: white;
+}
+
+#plugins tr.all-dependants-disabled .enable input {
+  pointer-events: auto;
+  opacity: 1.0;
+  visibility: visible;
+}
+
+#plugins tr.has-dependants input, #plugins tr.has-disabled-dependency .enable input {
+  pointer-events: none;
+  opacity: 0.2;
+}
+
+#plugins tr.has-disabled-dependency .enable input {
+  opacity: 0.4;
+}
+
+#plugins tr.deleted input {
+  visibility: hidden !important;
+}
+
+#plugins .dependant-list, #plugins .dependency-list {
+  display: none;
+}
+
+#plugins .enable-state-info, #plugins .uninstall-state-info {
+    padding: 5px 20px;
+    max-width: 70%;
+    border: solid 1px #f0ad4e;
+    border-radius: 3px;
+    text-align: center;
+}
+
+#plugins .enable-state-info {
+    float: left;
+}
+
+#plugins .uninstall-state-info {
+    float: right;
+}
+
+#plugins .plugin-dependency-info .title, #plugins .plugin-dependency-info .subtitle {
+    opacity: 0.7;
+}
+#plugins .plugin-dependency-info .title {
+    margin-bottom: 5px;
+    font-size: larger;
+    font-weight: bolder;
+}
+
+#plugins .plugin-dependency-info span {
+    margin: 5px 5px 0px 0px;
+    background-color: #337ab7;
+    display: inline-block;
+    padding: .2em .6em .3em;
+    font-size: 75%;
+    font-weight: 700;
+    line-height: 1;
+    color: #fff;
+    text-align: center;
+    white-space: nowrap;
+    vertical-align: baseline;
+    border-radius: .25em;
+}
 
 /* ========================= repeatable elements ========================= */
 
@@ -1690,3 +1770,20 @@ table#legend-table td {
     color: #f8f8f8;
     border: 1px solid #e39280;
 }
+
+.i18n {
+    display: none;
+}
+
+.alert {
+    padding: 15px;
+    margin-bottom: 20px;
+    border: 1px solid transparent;
+    border-radius: 4px;
+}
+
+.alert-warning {
+    color: #8a6d3b;
+    background-color: #fcf8e3;
+    border-color: #faebcc;
+}
\ No newline at end of file