Make use of HTML in outgoing emails optional

This will make it possible for gerrit-review.googlesource.com to turn
HTML off in the emails it sends until bugs in its EmailSender are
ironed out.

Bug: Issue 4589
Change-Id: Iadcfb5a38ac14044e0163a3f2db0c326ccda1f73

Documentation/config-gerrit.txt

@@ -3327,6 +3327,14 @@ and all other properties of section sendemail are ignored.
 +
 By default, true, allowing notifications to be sent.
 
+[[sendemail.html]]sendemail.html::
++
+If false, Gerrit will only send plain-text emails.
+If true, Gerrit will send multi-part emails with an HTML and
+plain text part.
++
+By default, true, allowing HTML in the emails Gerrit sends.
+
 [[sendemail.connectTimeout]]sendemail.connectTimeout::
 +
 The connection timeout of opening a socket connected to a

gerrit-server/src/main/java/com/google/gerrit/server/mail/AbandonedSender.java

@@ -51,11 +51,13 @@ public class AbandonedSender extends ReplyToChangeSender {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("Abandoned"));
-    appendHtml(soyHtmlTemplate("AbandonedHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("AbandonedHtml"));
+    }
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/AddKeySender.java

@@ -81,7 +81,9 @@ public class AddKeySender extends OutgoingEmail {
   @Override
   protected void format() throws EmailException {
     appendText(textTemplate("AddKey"));
-    appendHtml(soyHtmlTemplate("AddKeyHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("AddKeyHtml"));
+    }
   }
 
   public String getEmail() {
@@ -123,7 +125,7 @@ public class AddKeySender extends OutgoingEmail {
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/DeleteReviewerSender.java

@@ -66,7 +66,9 @@ public class DeleteReviewerSender extends ReplyToChangeSender {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("DeleteReviewer"));
-    appendHtml(soyHtmlTemplate("DeleteReviewerHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("DeleteReviewerHtml"));
+    }
   }
 
   public List<String> getReviewerNames() {
@@ -87,7 +89,7 @@ public class DeleteReviewerSender extends ReplyToChangeSender {
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/DeleteVoteSender.java

@@ -50,11 +50,13 @@ public class DeleteVoteSender extends ReplyToChangeSender {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("DeleteVote"));
-    appendHtml(soyHtmlTemplate("DeleteVoteHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("DeleteVoteHtml"));
+    }
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/EmailSettings.java

@@ -22,11 +22,13 @@ import org.eclipse.jgit.lib.Config;
 
 @Singleton
 public class EmailSettings {
+  public final boolean html;
   public final boolean includeDiff;
   public final int maximumDiffSize;
 
   @Inject
   EmailSettings(@GerritServerConfig Config cfg) {
+    html = cfg.getBoolean("sendemail", "html", true);
     includeDiff = cfg.getBoolean("sendemail", "includeDiff", false);
     maximumDiffSize = cfg.getInt("sendemail", "maximumDiffSize", 256 << 10);
   }

gerrit-server/src/main/java/com/google/gerrit/server/mail/NewChangeSender.java

@@ -68,7 +68,9 @@ public abstract class NewChangeSender extends ChangeEmail {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("NewChange"));
-    appendHtml(soyHtmlTemplate("NewChangeHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("NewChangeHtml"));
+    }
   }
 
   public List<String> getReviewerNames() {
@@ -89,7 +91,7 @@ public abstract class NewChangeSender extends ChangeEmail {
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

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

@@ -631,8 +631,12 @@ public abstract class OutgoingEmail {
     return obj != null ? obj.toString() : "";
   }
 
+  protected final boolean useHtml() {
+    return args.settings.html && supportsHtml();
+  }
+
   /** Override this method to enable HTML in a subclass. */
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return false;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/ReplacePatchSetSender.java

@@ -73,7 +73,9 @@ public class ReplacePatchSetSender extends ReplyToChangeSender {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("ReplacePatchSet"));
-    appendHtml(soyHtmlTemplate("ReplacePatchSetHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("ReplacePatchSetHtml"));
+    }
   }
 
   public List<String> getReviewerNames() {
@@ -97,7 +99,7 @@ public class ReplacePatchSetSender extends ReplyToChangeSender {
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/RestoredSender.java

@@ -50,11 +50,13 @@ public class RestoredSender extends ReplyToChangeSender {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("Restored"));
-    appendHtml(soyHtmlTemplate("RestoredHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("RestoredHtml"));
+    }
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/mail/RevertedSender.java

@@ -48,11 +48,13 @@ public class RevertedSender extends ReplyToChangeSender {
   @Override
   protected void formatChange() throws EmailException {
     appendText(textTemplate("Reverted"));
-    appendHtml(soyHtmlTemplate("RevertedHtml"));
+    if (useHtml()) {
+      appendHtml(soyHtmlTemplate("RevertedHtml"));
+    }
   }
 
   @Override
-  protected boolean useHtml() {
+  protected boolean supportsHtml() {
     return true;
   }
 }