Add sendemail.enable to disable email output

Some installations might be unable to connect to a SMTP relay,
but are still useful through the web page UI, provided that
reviewers check their dashboard periodically.  In such cases
we can't open a socket to a SMTP server, so we should bypass
any email sending code paths to prevent errors from filling
up the server logs.

Signed-off-by: Shawn O. Pearce <sop@google.com>

Documentation/config-gerrit.txt

@@ -372,6 +372,13 @@ By default, false, as not all instances will deploy repo.
 Section sendemail
 ~~~~~~~~~~~~~~~~~
 
+sendemail.enable::
++
+If false Gerrit will not send email messages, for any reason,
+and all other properties of section sendemail are ignored.
++
+By default, true, allowing notifications to be sent.
+
 sendemail.smtpServer::
 +
 Hostname (or IP address) of a SMTP server that will relay

src/main/java/com/google/gerrit/client/account/ContactPanel.java

@@ -137,7 +137,9 @@ class ContactPanel extends Composite {
     });
     final FlowPanel emailLine = new FlowPanel();
     emailLine.add(emailPick);
-    emailLine.add(registerNewEmail);
+    if (Common.getGerritConfig().isAllowRegisterNewEmail()) {
+      emailLine.add(registerNewEmail);
+    }
 
     row(infoPlainText, 0, Util.C.contactFieldFullName(), nameTxt);
     row(infoPlainText, 1, Util.C.contactFieldEmail(), emailLine);
@@ -261,8 +263,10 @@ class ContactPanel extends Composite {
       if (emailPick.getItemCount() > 0) {
         emailPick.setVisible(true);
         emailPick.setEnabled(true);
-        emailPick.addItem("... " + Util.C.buttonOpenRegisterNewEmail() + "  ",
-            Util.C.buttonOpenRegisterNewEmail());
+        if (Common.getGerritConfig().isAllowRegisterNewEmail()) {
+          final String t = Util.C.buttonOpenRegisterNewEmail();
+          emailPick.addItem("... " + t + "  ", t);
+        }
       } else {
         emailPick.setVisible(false);
       }
@@ -299,6 +303,10 @@ class ContactPanel extends Composite {
   }
 
   private void doRegisterNewEmail() {
+    if (!Common.getGerritConfig().isAllowRegisterNewEmail()) {
+      return;
+    }
+
     final AutoCenterDialogBox box = new AutoCenterDialogBox(true, true);
     final VerticalPanel body = new VerticalPanel();
 

src/main/java/com/google/gerrit/client/data/GerritConfig.java

@@ -29,6 +29,7 @@ public class GerritConfig implements Cloneable {
   protected List<ApprovalType> actionTypes;
   protected boolean useContributorAgreements;
   protected boolean useContactInfo;
+  protected boolean allowRegisterNewEmail;
   protected SystemConfig.LoginType loginType;
   protected boolean useRepoDownload;
   protected String gitDaemonUrl;
@@ -110,6 +111,14 @@ public class GerritConfig implements Cloneable {
     useContactInfo = r;
   }
 
+  public boolean isAllowRegisterNewEmail() {
+    return allowRegisterNewEmail;
+  }
+
+  public void setAllowRegisterNewEmail(final boolean r) {
+    allowRegisterNewEmail = r;
+  }
+
   public ApprovalType getApprovalType(final ApprovalCategory.Id id) {
     if (byCategoryId == null) {
       byCategoryId = new HashMap<ApprovalCategory.Id, ApprovalType>();

src/main/java/com/google/gerrit/server/GerritServer.java

@@ -678,6 +678,7 @@ public class GerritServer {
     r.setUseRepoDownload(getGerritConfig().getBoolean("repo", null,
         "showdownloadcommand", false));
     r.setUseContactInfo(getContactStoreURL() != null);
+    r.setAllowRegisterNewEmail(isOutgoingMailEnabled());
     r.setLoginType(getLoginType());
 
     final String gitwebUrl = getGerritConfig().getString("gitweb", null, "url");
@@ -693,7 +694,15 @@ public class GerritServer {
     Common.setGerritConfig(r);
   }
 
+  public boolean isOutgoingMailEnabled() {
+    return getGerritConfig().getBoolean("sendemail", null, "enable", true);
+  }
+
   public SMTPClient createOutgoingMail() throws EmailException {
+    if (!isOutgoingMailEnabled()) {
+      throw new EmailException("Sending email is disabled");
+    }
+
     final RepositoryConfig cfg = getGerritConfig();
     String smtpHost = cfg.getString("sendemail", null, "smtpserver");
     if (smtpHost == null) {

src/main/java/com/google/gerrit/server/mail/OutgoingEmail.java

@@ -112,6 +112,12 @@ public abstract class OutgoingEmail {
    * @throws EmailException
    */
   public void send() throws EmailException {
+    if (!server.isOutgoingMailEnabled()) {
+      // Server has explicitly disabled email sending.
+      //
+      return;
+    }
+
     init();
     format();
     if (shouldSendMessage()) {