diff --git a/src/infrastructure/markup/PhabricatorMarkupEngine.php b/src/infrastructure/markup/PhabricatorMarkupEngine.php
index 35de846650..5422870b68 100644
--- a/src/infrastructure/markup/PhabricatorMarkupEngine.php
+++ b/src/infrastructure/markup/PhabricatorMarkupEngine.php
@@ -1,714 +1,714 @@
 <?php
 
 /**
  * Manages markup engine selection, configuration, application, caching and
  * pipelining.
  *
  * @{class:PhabricatorMarkupEngine} can be used to render objects which
  * implement @{interface:PhabricatorMarkupInterface} in a batched, cache-aware
  * way. For example, if you have a list of comments written in remarkup (and
  * the objects implement the correct interface) you can render them by first
  * building an engine and adding the fields with @{method:addObject}.
  *
  *   $field  = 'field:body'; // Field you want to render. Each object exposes
  *                           // one or more fields of markup.
  *
  *   $engine = new PhabricatorMarkupEngine();
  *   foreach ($comments as $comment) {
  *     $engine->addObject($comment, $field);
  *   }
  *
  * Now, call @{method:process} to perform the actual cache/rendering
  * step. This is a heavyweight call which does batched data access and
  * transforms the markup into output.
  *
  *   $engine->process();
  *
  * Finally, do something with the results:
  *
  *   $results = array();
  *   foreach ($comments as $comment) {
  *     $results[] = $engine->getOutput($comment, $field);
  *   }
  *
  * If you have a single object to render, you can use the convenience method
  * @{method:renderOneObject}.
  *
  * @task markup Markup Pipeline
  * @task engine Engine Construction
  */
 final class PhabricatorMarkupEngine extends Phobject {
 
   private $objects = array();
   private $viewer;
   private $contextObject;
-  private $version = 19;
+  private $version = 20;
   private $engineCaches = array();
   private $auxiliaryConfig = array();
 
 
 /* -(  Markup Pipeline  )---------------------------------------------------- */
 
 
   /**
    * Convenience method for pushing a single object through the markup
    * pipeline.
    *
    * @param PhabricatorMarkupInterface  The object to render.
    * @param string                      The field to render.
    * @param PhabricatorUser             User viewing the markup.
    * @param object                      A context object for policy checks
    * @return string                     Marked up output.
    * @task markup
    */
   public static function renderOneObject(
     PhabricatorMarkupInterface $object,
     $field,
     PhabricatorUser $viewer,
     $context_object = null) {
     return id(new PhabricatorMarkupEngine())
       ->setViewer($viewer)
       ->setContextObject($context_object)
       ->addObject($object, $field)
       ->process()
       ->getOutput($object, $field);
   }
 
 
   /**
    * Queue an object for markup generation when @{method:process} is
    * called. You can retrieve the output later with @{method:getOutput}.
    *
    * @param PhabricatorMarkupInterface  The object to render.
    * @param string                      The field to render.
    * @return this
    * @task markup
    */
   public function addObject(PhabricatorMarkupInterface $object, $field) {
     $key = $this->getMarkupFieldKey($object, $field);
     $this->objects[$key] = array(
       'object' => $object,
       'field'  => $field,
     );
 
     return $this;
   }
 
 
   /**
    * Process objects queued with @{method:addObject}. You can then retrieve
    * the output with @{method:getOutput}.
    *
    * @return this
    * @task markup
    */
   public function process() {
     $keys = array();
     foreach ($this->objects as $key => $info) {
       if (!isset($info['markup'])) {
         $keys[] = $key;
       }
     }
 
     if (!$keys) {
       return $this;
     }
 
     $objects = array_select_keys($this->objects, $keys);
 
     // Build all the markup engines. We need an engine for each field whether
     // we have a cache or not, since we still need to postprocess the cache.
     $engines = array();
     foreach ($objects as $key => $info) {
       $engines[$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.
     $blocks = $this->loadPreprocessorCaches($engines, $objects);
     $blocks = mpull($blocks, 'getCacheData');
 
     $this->engineCaches = $blocks;
 
     // Finalize the output.
     foreach ($objects as $key => $info) {
       $engine = $engines[$key];
       $field = $info['field'];
       $object = $info['object'];
 
       $output = $engine->postprocessText($blocks[$key]);
       $output = $object->didMarkupText($field, $output, $engine);
       $this->objects[$key]['output'] = $output;
     }
 
     return $this;
   }
 
 
   /**
    * Get the output of markup processing for a field queued with
    * @{method:addObject}. Before you can call this method, you must call
    * @{method:process}.
    *
    * @param PhabricatorMarkupInterface  The object to retrieve.
    * @param string                      The field to retrieve.
    * @return string                     Processed output.
    * @task markup
    */
   public function getOutput(PhabricatorMarkupInterface $object, $field) {
     $key = $this->getMarkupFieldKey($object, $field);
     $this->requireKeyProcessed($key);
 
     return $this->objects[$key]['output'];
   }
 
 
   /**
    * Retrieve engine metadata for a given field.
    *
    * @param PhabricatorMarkupInterface  The object to retrieve.
    * @param string                      The field to retrieve.
    * @param string                      The engine metadata field to retrieve.
    * @param wild                        Optional default value.
    * @task markup
    */
   public function getEngineMetadata(
     PhabricatorMarkupInterface $object,
     $field,
     $metadata_key,
     $default = null) {
 
     $key = $this->getMarkupFieldKey($object, $field);
     $this->requireKeyProcessed($key);
 
     return idx($this->engineCaches[$key]['metadata'], $metadata_key, $default);
   }
 
 
   /**
    * @task markup
    */
   private function requireKeyProcessed($key) {
     if (empty($this->objects[$key])) {
       throw new Exception(
         pht(
           "Call %s before using results (key = '%s').",
           'addObject()',
           $key));
     }
 
     if (!isset($this->objects[$key]['output'])) {
       throw new PhutilInvalidStateException('process');
     }
   }
 
 
   /**
    * @task markup
    */
   private function getMarkupFieldKey(
     PhabricatorMarkupInterface $object,
     $field) {
 
     static $custom;
     if ($custom === null) {
       $custom = array_merge(
         self::loadCustomInlineRules(),
         self::loadCustomBlockRules());
 
       $custom = mpull($custom, 'getRuleVersion', null);
       ksort($custom);
       $custom = PhabricatorHash::digestForIndex(serialize($custom));
     }
 
     return $object->getMarkupFieldKey($field).'@'.$this->version.'@'.$custom;
   }
 
 
   /**
    * @task markup
    */
   private function loadPreprocessorCaches(array $engines, array $objects) {
     $blocks = array();
 
     $use_cache = array();
     foreach ($objects as $key => $info) {
       if ($info['object']->shouldUseMarkupCache($info['field'])) {
         $use_cache[$key] = true;
       }
     }
 
     if ($use_cache) {
       try {
         $blocks = id(new PhabricatorMarkupCache())->loadAllWhere(
           'cacheKey IN (%Ls)',
           array_keys($use_cache));
         $blocks = mpull($blocks, null, 'getCacheKey');
       } catch (Exception $ex) {
         phlog($ex);
       }
     }
 
     $is_readonly = PhabricatorEnv::isReadOnly();
 
     foreach ($objects as $key => $info) {
       // False check in case MySQL doesn't support unicode characters
       // in the string (T1191), resulting in unserialize returning false.
       if (isset($blocks[$key]) && $blocks[$key]->getCacheData() !== false) {
         // If we already have a preprocessing cache, we don't need to rebuild
         // it.
         continue;
       }
 
       $text = $info['object']->getMarkupText($info['field']);
       $data = $engines[$key]->preprocessText($text);
 
       // NOTE: This is just debugging information to help sort out cache issues.
       // If one machine is misconfigured and poisoning caches you can use this
       // field to hunt it down.
 
       $metadata = array(
         'host' => php_uname('n'),
       );
 
       $blocks[$key] = id(new PhabricatorMarkupCache())
         ->setCacheKey($key)
         ->setCacheData($data)
         ->setMetadata($metadata);
 
       if (isset($use_cache[$key]) && !$is_readonly) {
         // This is just filling a cache and always safe, even on a read pathway.
         $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
           $blocks[$key]->replace();
         unset($unguarded);
       }
     }
 
     return $blocks;
   }
 
 
   /**
    * Set the viewing user. Used to implement object permissions.
    *
    * @param PhabricatorUser The viewing user.
    * @return this
    * @task markup
    */
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   /**
    * Set the context object. Used to implement object permissions.
    *
    * @param The object in which context this remarkup is used.
    * @return this
    * @task markup
    */
   public function setContextObject($object) {
     $this->contextObject = $object;
     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  )------------------------------------------------ */
 
 
 
   /**
    * @task engine
    */
   public static function newManiphestMarkupEngine() {
     return self::newMarkupEngine(array(
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newPhrictionMarkupEngine() {
     return self::newMarkupEngine(array(
       'header.generate-toc' => true,
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newPhameMarkupEngine() {
     return self::newMarkupEngine(
       array(
         'macros' => false,
         'uri.full' => true,
         'uri.same-window' => true,
         'uri.base' => PhabricatorEnv::getURI('/'),
       ));
   }
 
 
   /**
    * @task engine
    */
   public static function newFeedMarkupEngine() {
     return self::newMarkupEngine(
       array(
         'macros'      => false,
         'youtube'     => false,
       ));
   }
 
   /**
    * @task engine
    */
   public static function newCalendarMarkupEngine() {
     return self::newMarkupEngine(array(
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newDifferentialMarkupEngine(array $options = array()) {
     return self::newMarkupEngine(array(
       'differential.diff' => idx($options, 'differential.diff'),
     ));
   }
 
 
   /**
    * @task engine
    */
   public static function newDiffusionMarkupEngine(array $options = array()) {
     return self::newMarkupEngine(array(
       'header.generate-toc' => true,
     ));
   }
 
   /**
    * @task engine
    */
   public static function getEngine($ruleset = 'default') {
     static $engines = array();
     if (isset($engines[$ruleset])) {
       return $engines[$ruleset];
     }
 
     $engine = null;
     switch ($ruleset) {
       case 'default':
         $engine = self::newMarkupEngine(array());
         break;
       case 'feed':
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('autoplay.disable', true);
         break;
       case 'nolinebreaks':
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('preserve-linebreaks', false);
         break;
       case 'diffusion-readme':
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('preserve-linebreaks', false);
         $engine->setConfig('header.generate-toc', true);
         break;
       case 'diviner':
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('preserve-linebreaks', false);
   //    $engine->setConfig('diviner.renderer', new DivinerDefaultRenderer());
         $engine->setConfig('header.generate-toc', true);
         break;
       case 'extract':
         // Engine used for reference/edge extraction. Turn off anything which
         // is slow and doesn't change reference extraction.
         $engine = self::newMarkupEngine(array());
         $engine->setConfig('pygments.enabled', false);
         break;
       default:
         throw new Exception(pht('Unknown engine ruleset: %s!', $ruleset));
     }
 
     $engines[$ruleset] = $engine;
     return $engine;
   }
 
   /**
    * @task engine
    */
   private static function getMarkupEngineDefaultConfiguration() {
     return array(
       'pygments'      => PhabricatorEnv::getEnvConfig('pygments.enabled'),
       'youtube'       => PhabricatorEnv::getEnvConfig(
         'remarkup.enable-embedded-youtube'),
       'differential.diff' => null,
       'header.generate-toc' => false,
       'macros'        => true,
       'uri.allowed-protocols' => PhabricatorEnv::getEnvConfig(
         'uri.allowed-protocols'),
       'uri.full' => false,
       'syntax-highlighter.engine' => PhabricatorEnv::getEnvConfig(
         'syntax-highlighter.engine'),
       'preserve-linebreaks' => true,
     );
   }
 
 
   /**
    * @task engine
    */
   public static function newMarkupEngine(array $options) {
     $options += self::getMarkupEngineDefaultConfiguration();
 
     $engine = new PhutilRemarkupEngine();
 
     $engine->setConfig('preserve-linebreaks', $options['preserve-linebreaks']);
 
     $engine->setConfig('pygments.enabled', $options['pygments']);
     $engine->setConfig(
       'uri.allowed-protocols',
       $options['uri.allowed-protocols']);
     $engine->setConfig('differential.diff', $options['differential.diff']);
     $engine->setConfig('header.generate-toc', $options['header.generate-toc']);
     $engine->setConfig(
       'syntax-highlighter.engine',
       $options['syntax-highlighter.engine']);
 
     $style_map = id(new PhabricatorDefaultSyntaxStyle())
       ->getRemarkupStyleMap();
     $engine->setConfig('phutil.codeblock.style-map', $style_map);
 
     $engine->setConfig('uri.full', $options['uri.full']);
 
     if (isset($options['uri.base'])) {
       $engine->setConfig('uri.base', $options['uri.base']);
     }
 
     if (isset($options['uri.same-window'])) {
       $engine->setConfig('uri.same-window', $options['uri.same-window']);
     }
 
     $rules = array();
     $rules[] = new PhutilRemarkupEscapeRemarkupRule();
     $rules[] = new PhutilRemarkupMonospaceRule();
 
 
     $rules[] = new PhutilRemarkupDocumentLinkRule();
     $rules[] = new PhabricatorNavigationRemarkupRule();
     $rules[] = new PhabricatorKeyboardRemarkupRule();
     $rules[] = new PhabricatorConfigRemarkupRule();
 
     if ($options['youtube']) {
       $rules[] = new PhabricatorYoutubeRemarkupRule();
     }
 
     $rules[] = new PhabricatorIconRemarkupRule();
     $rules[] = new PhabricatorEmojiRemarkupRule();
     $rules[] = new PhabricatorHandleRemarkupRule();
 
     $applications = PhabricatorApplication::getAllInstalledApplications();
     foreach ($applications as $application) {
       foreach ($application->getRemarkupRules() as $rule) {
         $rules[] = $rule;
       }
     }
 
     $rules[] = new PhutilRemarkupHyperlinkRule();
 
     if ($options['macros']) {
       $rules[] = new PhabricatorImageMacroRemarkupRule();
       $rules[] = new PhabricatorMemeRemarkupRule();
     }
 
     $rules[] = new PhutilRemarkupBoldRule();
     $rules[] = new PhutilRemarkupItalicRule();
     $rules[] = new PhutilRemarkupDelRule();
     $rules[] = new PhutilRemarkupUnderlineRule();
     $rules[] = new PhutilRemarkupHighlightRule();
     $rules[] = new PhutilRemarkupAnchorRule();
 
     foreach (self::loadCustomInlineRules() as $rule) {
       $rules[] = clone $rule;
     }
 
     $blocks = array();
     $blocks[] = new PhutilRemarkupQuotesBlockRule();
     $blocks[] = new PhutilRemarkupReplyBlockRule();
     $blocks[] = new PhutilRemarkupLiteralBlockRule();
     $blocks[] = new PhutilRemarkupHeaderBlockRule();
     $blocks[] = new PhutilRemarkupHorizontalRuleBlockRule();
     $blocks[] = new PhutilRemarkupListBlockRule();
     $blocks[] = new PhutilRemarkupCodeBlockRule();
     $blocks[] = new PhutilRemarkupNoteBlockRule();
     $blocks[] = new PhutilRemarkupTableBlockRule();
     $blocks[] = new PhutilRemarkupSimpleTableBlockRule();
     $blocks[] = new PhutilRemarkupInterpreterBlockRule();
     $blocks[] = new PhutilRemarkupDefaultBlockRule();
 
     foreach (self::loadCustomBlockRules() as $rule) {
       $blocks[] = $rule;
     }
 
     foreach ($blocks as $block) {
       $block->setMarkupRules($rules);
     }
 
     $engine->setBlockRules($blocks);
 
     return $engine;
   }
 
   public static function extractPHIDsFromMentions(
     PhabricatorUser $viewer,
     array $content_blocks) {
 
     $mentions = array();
 
     $engine = self::newDifferentialMarkupEngine();
     $engine->setConfig('viewer', $viewer);
 
     foreach ($content_blocks as $content_block) {
       $engine->markupText($content_block);
       $phids = $engine->getTextMetadata(
         PhabricatorMentionRemarkupRule::KEY_MENTIONED,
         array());
       $mentions += $phids;
     }
 
     return $mentions;
   }
 
   public static function extractFilePHIDsFromEmbeddedFiles(
     PhabricatorUser $viewer,
     array $content_blocks) {
     $files = array();
 
     $engine = self::newDifferentialMarkupEngine();
     $engine->setConfig('viewer', $viewer);
 
     foreach ($content_blocks as $content_block) {
       $engine->markupText($content_block);
       $phids = $engine->getTextMetadata(
         PhabricatorEmbedFileRemarkupRule::KEY_EMBED_FILE_PHIDS,
         array());
       foreach ($phids as $phid) {
         $files[$phid] = $phid;
       }
     }
 
     return array_values($files);
   }
 
   public static function summarizeSentence($corpus) {
     $corpus = trim($corpus);
     $blocks = preg_split('/\n+/', $corpus, 2);
     $block = head($blocks);
 
     $sentences = preg_split(
       '/\b([.?!]+)\B/u',
       $block,
       2,
       PREG_SPLIT_DELIM_CAPTURE);
 
     if (count($sentences) > 1) {
       $result = $sentences[0].$sentences[1];
     } else {
       $result = head($sentences);
     }
 
     return id(new PhutilUTF8StringTruncator())
       ->setMaximumGlyphs(128)
       ->truncateString($result);
   }
 
   /**
    * Produce a corpus summary, in a way that shortens the underlying text
    * without truncating it somewhere awkward.
    *
    * TODO: We could do a better job of this.
    *
    * @param string  Remarkup corpus to summarize.
    * @return string Summarized corpus.
    */
   public static function summarize($corpus) {
 
     // Major goals here are:
     //  - Don't split in the middle of a character (utf-8).
     //  - Don't split in the middle of, e.g., **bold** text, since
     //    we end up with hanging '**' in the summary.
     //  - Try not to pick an image macro, header, embedded file, etc.
     //  - Hopefully don't return too much text. We don't explicitly limit
     //    this right now.
 
     $blocks = preg_split("/\n *\n\s*/", $corpus);
 
     $best = null;
     foreach ($blocks as $block) {
       // This is a test for normal spaces in the block, i.e. a heuristic to
       // distinguish standard paragraphs from things like image macros. It may
       // not work well for non-latin text. We prefer to summarize with a
       // paragraph of normal words over an image macro, if possible.
       $has_space = preg_match('/\w\s\w/', $block);
 
       // This is a test to find embedded images and headers. We prefer to
       // summarize with a normal paragraph over a header or an embedded object,
       // if possible.
       $has_embed = preg_match('/^[{=]/', $block);
 
       if ($has_space && !$has_embed) {
         // This seems like a good summary, so return it.
         return $block;
       }
 
       if (!$best) {
         // This is the first block we found; if everything is garbage just
         // use the first block.
         $best = $block;
       }
     }
 
     return $best;
   }
 
   private static function loadCustomInlineRules() {
     return id(new PhutilClassMapQuery())
       ->setAncestorClass('PhabricatorRemarkupCustomInlineRule')
       ->execute();
   }
 
   private static function loadCustomBlockRules() {
     return id(new PhutilClassMapQuery())
       ->setAncestorClass('PhabricatorRemarkupCustomBlockRule')
       ->execute();
   }
 
   public static function digestRemarkupContent($object, $content) {
     $parts = array();
     $parts[] = get_class($object);
 
     if ($object instanceof PhabricatorLiskDAO) {
       $parts[] = $object->getID();
     }
 
     $parts[] = $content;
 
     $message = implode("\n", $parts);
 
     return PhabricatorHash::digestWithNamedKey($message, 'remarkup');
   }
 
 }
diff --git a/src/infrastructure/markup/blockrule/PhutilRemarkupQuotedBlockRule.php b/src/infrastructure/markup/blockrule/PhutilRemarkupQuotedBlockRule.php
index ed87f7063d..9f2bd7a297 100644
--- a/src/infrastructure/markup/blockrule/PhutilRemarkupQuotedBlockRule.php
+++ b/src/infrastructure/markup/blockrule/PhutilRemarkupQuotedBlockRule.php
@@ -1,108 +1,110 @@
 <?php
 
 abstract class PhutilRemarkupQuotedBlockRule
   extends PhutilRemarkupBlockRule {
 
   final public function supportsChildBlocks() {
     return true;
   }
 
   final protected function normalizeQuotedBody($text) {
     $text = phutil_split_lines($text, true);
     foreach ($text as $key => $line) {
       $text[$key] = substr($line, 1);
     }
 
     // If every line in the block is empty or begins with at least one leading
     // space, strip the initial space off each line. When we quote text, we
     // normally add "> " (with a space) to the beginning of each line, which
     // can disrupt some other rules. If the block appears to have this space
     // in front of each line, remove it.
 
     $strip_space = true;
     foreach ($text as $key => $line) {
       $len = strlen($line);
 
       if (!$len) {
         // We'll still strip spaces if there are some completely empty
         // lines, they may have just had trailing whitespace trimmed.
         continue;
       }
 
       // If this line is part of a nested quote block, just ignore it when
       // realigning this quote block. It's either an author attribution
       // line with ">>!", or we'll deal with it in a subrule when processing
       // the nested quote block.
       if ($line[0] == '>') {
         continue;
       }
 
       if ($line[0] == ' ' || $line[0] == "\n") {
         continue;
       }
 
       // The first character of this line is something other than a space, so
       // we can't strip spaces.
       $strip_space = false;
       break;
     }
 
     if ($strip_space) {
       foreach ($text as $key => $line) {
         $len = strlen($line);
         if (!$len) {
           continue;
         }
 
         if ($line[0] !== ' ') {
           continue;
         }
 
         $text[$key] = substr($line, 1);
       }
     }
 
     // Strip leading empty lines.
     foreach ($text as $key => $line) {
       if (!strlen(trim($line))) {
         unset($text[$key]);
+      } else {
+        break;
       }
     }
 
     return implode('', $text);
   }
 
   final protected function getQuotedText($text) {
     $text = rtrim($text, "\n");
 
     $no_whitespace = array(
       // For readability, we render nested quotes as ">> quack",
       // not "> > quack".
       '>' => true,
 
       // If the line is empty except for a newline, do not add an
       // unnecessary dangling space.
       "\n" => true,
     );
 
     $text = phutil_split_lines($text, true);
     foreach ($text as $key => $line) {
       $c = null;
       if (isset($line[0])) {
         $c = $line[0];
       } else {
         $c = null;
       }
 
       if (isset($no_whitespace[$c])) {
         $text[$key] = '>'.$line;
       } else {
         $text[$key] = '> '.$line;
       }
     }
     $text = implode('', $text);
 
     return $text;
   }
 
 }
diff --git a/src/infrastructure/markup/remarkup/__tests__/remarkup/quoted-paragraphs.txt b/src/infrastructure/markup/remarkup/__tests__/remarkup/quoted-paragraphs.txt
new file mode 100644
index 0000000000..de597b5e0a
--- /dev/null
+++ b/src/infrastructure/markup/remarkup/__tests__/remarkup/quoted-paragraphs.txt
@@ -0,0 +1,11 @@
+> x
+>
+> y
+~~~~~~~~~~
+<blockquote><p>x</p>
+
+<p>y</p></blockquote>
+~~~~~~~~~~
+> x
+>
+> y