Remove extra container tag on HandleListViews rendering from ModularTransactions in text mode

Summary:
Fixes T12082. Ref T11114. When modular transaction render a handle list, they use HandleListView, which has a text mode.

However, the HandleListView is a TagView, and currently TagViews always render a tag of some kind. Allow them to return `null` to decline to render any tag.

Test Plan:
  - Added a pile of debugging stuff to `ApplicationTransactionEditor` to throw during mail generation.
  - Added a reviewer to a revision.
  - Used `bin/worker execute --id ...` to hit the mail generation repeatedly.
  - Before patch: mail generated with a <span>, even in text mode.
  - After patch: clean mail generation.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12082, T11114

Differential Revision: https://secure.phabricator.com/D17162

src/applications/phid/view/PHUIHandleListView.php

@@ -38,10 +38,14 @@ final class PHUIHandleListView
   }
 
   protected function getTagName() {
-    // TODO: It would be nice to render this with a proper <ul />, at least in
+    if ($this->getAsText()) {
-    // block mode, but don't stir the waters up too much for now.
+      return null;
+    } else {
+      // TODO: It would be nice to render this with a proper <ul />, at least
+      // in block mode, but don't stir the waters up too much for now.
       return 'span';
     }
+  }
 
   protected function getTagContent() {
     $list = $this->handleList;

src/view/AphrontTagView.php

@@ -92,6 +92,15 @@ abstract class AphrontTagView extends AphrontView {
   final public function render() {
     $this->willRender();
 
+    // A tag view may render no tag at all. For example, the HandleListView is
+    // a container which renders a tag in HTML mode, but can also render in
+    // text mode without producing a tag. When a tag view has no tag name, just
+    // return the tag content as though the view did not exist.
+    $tag_name = $this->getTagName();
+    if ($tag_name === null) {
+      return $this->getTagContent();
+    }
+
     $attributes = $this->getTagAttributes();
 
     $implode = array('class', 'sigil');
@@ -147,7 +156,7 @@ abstract class AphrontTagView extends AphrontView {
     }
 
     return javelin_tag(
-      $this->getTagName(),
+      $tag_name,
       $attributes,
       $this->getTagContent());
   }