Fix possible recursive embeds in Dashboard text panels

Summary:
We currently detect tab panels embedding themselves, but do not detect text panels embedding themselves with `{Wxx}`.

Detect these self-embedding panels.

I had to add a bit of a hack to pass the parent panel PHIDs to the rule. Generally, I got the Markup API kind of wrong and want to update it, I'll file a followup with details about how I'd like to move forward.

Test Plan:
Created a text panel embedding itself, a tab panel embedding a text panel embedding itself, a tab panel embedding a text panel embedding the tab panel, etc.

Rendered all panels standalone and as `{Wxx}` from a different context.

{F761158}

{F761159}

{F761160}

{F761161}

{F761162}

Reviewers: chad, jbeta

Reviewed By: chad, jbeta

Differential Revision: https://secure.phabricator.com/D13999

src/applications/dashboard/paneltype/PhabricatorDashboardTextPanelType.php

@@ -37,11 +37,25 @@ final class PhabricatorDashboardTextPanelType
     PhabricatorDashboardPanelRenderingEngine $engine) {
 
     $text = $panel->getProperty('text', '');
+    $oneoff = id(new PhabricatorMarkupOneOff())->setContent($text);
+    $field = 'default';
 
-    $text_content = PhabricatorMarkupEngine::renderOneObject(
-      id(new PhabricatorMarkupOneOff())->setContent($text),
-      'default',
-      $viewer);
+    // NOTE: We're taking extra steps here to prevent creation of a text panel
+    // which embeds itself using `{Wnnn}`, recursing indefinitely.
+
+    $parent_key = PhabricatorDashboardRemarkupRule::KEY_PARENT_PANEL_PHIDS;
+    $parent_phids = $engine->getParentPanelPHIDs();
+    $parent_phids[] = $panel->getPHID();
+
+    $markup_engine = id(new PhabricatorMarkupEngine())
+      ->setViewer($viewer)
+      ->setContextObject($panel)
+      ->setAuxiliaryConfig($parent_key, $parent_phids);
+
+    $text_content = $markup_engine
+      ->addObject($oneoff, $field)
+      ->process()
+      ->getOutput($oneoff, $field);
 
     return id(new PHUIPropertyListView())
       ->addTextContent($text_content);

src/applications/dashboard/remarkup/PhabricatorDashboardRemarkupRule.php

@@ -3,6 +3,8 @@
 final class PhabricatorDashboardRemarkupRule
   extends PhabricatorObjectRemarkupRule {
 
+  const KEY_PARENT_PANEL_PHIDS = 'dashboard.parentPanelPHIDs';
+
   protected function getObjectNamePrefix() {
     return 'W';
   }
@@ -21,12 +23,16 @@ final class PhabricatorDashboardRemarkupRule
     PhabricatorObjectHandle $handle,
     $options) {
 
-    $viewer = $this->getEngine()->getConfig('viewer');
+    $engine = $this->getEngine();
+    $viewer = $engine->getConfig('viewer');
+
+    $parent_key = self::KEY_PARENT_PANEL_PHIDS;
+    $parent_phids = $engine->getConfig($parent_key, array());
 
     return id(new PhabricatorDashboardPanelRenderingEngine())
       ->setViewer($viewer)
       ->setPanel($object)
-      ->setParentPanelPHIDs(array())
+      ->setParentPanelPHIDs($parent_phids)
       ->renderPanel();
 
   }

src/infrastructure/markup/PhabricatorMarkupEngine.php

@@ -44,6 +44,7 @@ final class PhabricatorMarkupEngine extends Phobject {
   private $contextObject;
   private $version = 15;
   private $engineCaches = array();
+  private $auxiliaryConfig = array();
 
 
 /* -(  Markup Pipeline  )---------------------------------------------------- */
@@ -122,6 +123,10 @@ final class PhabricatorMarkupEngine extends Phobject {
       $engines[$key] = $info['object']->newMarkupEngine($info['field']);
       $engines[$key]->setConfig('viewer', $this->viewer);
       $engines[$key]->setConfig('contextObject', $this->contextObject);
+
+      foreach ($this->auxiliaryConfig as $aux_key => $aux_value) {
+        $engines[$key]->setConfig($aux_key, $aux_value);
+      }
     }
 
     // Load or build the preprocessor caches.
@@ -310,6 +315,12 @@ final class PhabricatorMarkupEngine extends Phobject {
     return $this;
   }
 
+  public function setAuxiliaryConfig($key, $value) {
+    // TODO: This is gross and should be removed. Avoid use.
+    $this->auxiliaryConfig[$key] = $value;
+    return $this;
+  }
+
 
 /* -(  Engine Construction  )------------------------------------------------ */