Improve linebreak / paragraph behavior.

src/applications/differential/parser/markup/DifferentialMarkupEngineFactory.php

@@ -21,6 +21,8 @@ class DifferentialMarkupEngineFactory {
   public function newDifferentialCommentMarkupEngine() {
     $engine = new PhutilRemarkupEngine();
 
+    $engine->setConfig('preserve-linebreaks', true);
+
     $rules = array();
     $rules[] = new PhutilRemarkupRuleEscapeRemarkup();
     $rules[] = new PhutilRemarkupRuleHyperlink();

src/applications/differential/view/revisioncomment/DifferentialRevisionCommentView.php

@@ -156,7 +156,11 @@ final class DifferentialRevisionCommentView extends AphrontView {
           $inline_render[] =
             '<tr>'.
               '<td class="inline-line-number">'.$lines.'</td>'.
-              '<td>'.$inline_content.'</td>'.
+              '<td>'.
+                '<div class="phabricator-remarkup">'.
+                  $inline_content.
+                '</div>'.
+              '</td>'.
             '</tr>';
         }
       }

webroot/rsrc/css/application/differential/revision-comment.css

@@ -42,10 +42,7 @@
   overflow: hidden;
 }
 
-.differential-comment-core .phabricator-remarkup p {
+.differential-comment-content .phabricator-remarkup code,
-  margin: 0.35em 0;
-}
-
 .differential-comment-core .phabricator-remarkup code {
    width: 88ex;
    width: 81ch;

webroot/rsrc/css/core/remarkup.css

@@ -7,7 +7,11 @@
 }
 
 .phabricator-remarkup p {
-  margin: 0 0 .75em;
+  margin: 0 0 1em;
+}
+
+.phabricator-remarkup p:last-child {
+  margin-bottom: 0;
 }
 
 .phabricator-remarkup code {