fix: prevent watching from applying to all jobs

Fixes the watching feature so that when a user watches
a given job, it only applies to that job. Previously,
when a job was watched, the project was not stored in
the user property, so it would end up watching all jobs.

src/main/java/hudson/plugins/emailext/ExtendedEmailPublisher.java

@@ -368,7 +368,11 @@ public void setMatrixTriggerMode(MatrixTriggerMode matrixTriggerMode) {
     @NonNull
     @Override
     public Collection<? extends Action> getProjectActions(AbstractProject<?, ?> project) {
-        return Collections.singletonList(new EmailExtWatchAction(project));
+        EmailExtWatchAction action = project.getAction(EmailExtWatchAction.class);
+        if (action == null) {
+            action = new EmailExtWatchAction(project);
+        }
+        return Collections.singletonList(action);
     }
 
     public void debug(PrintStream p, String format, Object... args) {

src/main/java/hudson/plugins/emailext/watching/EmailExtWatchAction.java

@@ -35,11 +35,13 @@ public class EmailExtWatchAction implements Action {
      */
     public static class UserProperty extends hudson.model.UserProperty {
         private List<EmailTrigger> triggers = new ArrayList<>();
+        private String projectName;
 
-        public UserProperty(List<EmailTrigger> triggers) {
+        public UserProperty(String projectId, List<EmailTrigger> triggers) {
             if (triggers != null) {
                 this.triggers = Collections.unmodifiableList(triggers);
             }
+            this.projectName = projectId;
         }
 
         @Exported
@@ -51,6 +53,14 @@ private void clearTriggers() {
             triggers = Collections.emptyList();
         }
 
+        public String getProjectName() {
+            return projectName;
+        }
+
+        public void setProjectName(String projectName) {
+            this.projectName = projectName;
+        }
+
         @Extension
         public static final class DescriptorImpl extends UserPropertyDescriptor {
 
@@ -66,20 +76,20 @@ public String getDisplayName() {
 
             @Override
             public UserProperty newInstance(User user) {
-                return new UserProperty(null);
+                return new UserProperty("", null);
             }
 
             @NonNull
             @Override
             public UserProperty newInstance(StaplerRequest req, @NonNull JSONObject json) throws FormException {
                 List<EmailTrigger> triggers =
                         req != null ? req.bindJSONToList(EmailTrigger.class, json) : Collections.emptyList();
-                return new UserProperty(triggers);
+                return new UserProperty("", triggers);
             }
         }
     }
 
-    private AbstractProject<?, ?> project;
+    private final AbstractProject<?, ?> project;
 
     public EmailExtWatchAction(AbstractProject<?, ?> project) {
         this.project = project;
@@ -114,15 +124,14 @@ public boolean isWatching() {
     }
 
     public List<EmailTrigger> getTriggers() {
-        List<EmailTrigger> triggers = null;
         User current = User.current();
         if (current != null) {
             UserProperty p = current.getProperty(UserProperty.class);
-            if (p != null) {
-                triggers = p.getTriggers();
+            if (p != null && p.getProjectName().equalsIgnoreCase(project.getFullName())) {
+                return p.getTriggers();
             }
         }
-        return triggers;
+        return null;
     }
 
     public EmailExtWatchJobProperty getJobProperty() throws IOException {
@@ -135,12 +144,11 @@ public EmailExtWatchJobProperty getJobProperty() throws IOException {
     }
 
     public Mailer.UserProperty getMailerProperty() {
-        Mailer.UserProperty prop = null;
         User current = User.current();
         if (current != null) {
-            prop = current.getProperty(Mailer.UserProperty.class);
+            return current.getProperty(Mailer.UserProperty.class);
         }
-        return prop;
+        return null;
     }
 
     public ExtendedEmailPublisher getPublisher() {
@@ -205,7 +213,7 @@ public void doConfigSubmit(StaplerRequest req, StaplerResponse rsp) throws IOExc
                 }
 
                 startWatching();
-                user.addProperty(new UserProperty(triggers));
+                user.addProperty(new UserProperty(project.getFullName(), triggers));
             }
         }
         rsp.sendRedirect(project.getAbsoluteUrl());

src/main/java/hudson/plugins/emailext/watching/EmailExtWatchJobProperty.java

@@ -33,36 +33,42 @@ public List<String> getWatchers() {
 
     public void addWatcher(User user) {
         String existing = null;
-        for (String u : watchers) {
-            if (u.compareTo(user.getId()) == 0) {
-                existing = u;
-                break;
+        synchronized (watchers) {
+            for (String u : watchers) {
+                if (u.compareTo(user.getId()) == 0) {
+                    existing = u;
+                    break;
+                }
             }
-        }
 
-        if (existing == null) {
-            watchers.add(user.getId());
+            if (existing == null) {
+                watchers.add(user.getId());
+            }
         }
     }
 
     public void removeWatcher(User user) {
         String remove = null;
-        for (String u : watchers) {
-            if (u.compareTo(user.getId()) == 0) {
-                remove = u;
-                break;
+        synchronized (watchers) {
+            for (String u : watchers) {
+                if (u.compareTo(user.getId()) == 0) {
+                    remove = u;
+                    break;
+                }
             }
-        }
 
-        if (remove != null) {
-            watchers.remove(user.getId());
+            if (remove != null) {
+                watchers.remove(user.getId());
+            }
         }
     }
 
     public boolean isWatching(User user) {
-        for (String u : watchers) {
-            if (u.compareTo(user.getId()) == 0) {
-                return true;
+        synchronized (watchers) {
+            for (String u : watchers) {
+                if (u.compareTo(user.getId()) == 0) {
+                    return true;
+                }
             }
         }
         return false;

src/main/resources/hudson/plugins/emailext/watching/EmailExtWatchAction/index.groovy

@@ -45,7 +45,7 @@ l.layout(norefresh: true) {
 
                     f.entry(title: _("Content Token Reference"), help: descriptor.getHelpFile('tokens'))
                     def triggers = hudson.plugins.emailext.plugins.EmailTrigger.all().findAll { t -> t.isWatchable() }
-                    def configuredTriggers = (my != null && my.triggers.size() > 0) ? my.triggers : []
+                    def configuredTriggers = (my != null && my?.triggers?.size() > 0) ? my.triggers : []
                     // do we want to filter the triggers somehow so that only some show up?
 
                     showSendTo = false