Test cases and fixes for Atom and RSS content decoding.

Fix extraction of Atom <content type="text"> and <content type="html">; we were failing to escape plaintext source data to HTML, and doing an extraneous double-deescape on HTML source resulting in breakage of notices containing text that looks like HTML. Only <content type="xhtml"> was working correctly previously.
Fixes for RSS2 content processing: we were failing to load <content:encoded> at all due to using wrong element name, and were applying an extraneous de-escape for <description> rather than the escaping that is required to turn plaintext into HTML. (Per spec, <description> must be plaintext.)

2 files changed, 21 insertions, 5 deletions

diff --git a/lib/activity.php b/lib/activity.php
index 5d6230c6d..27f09ab4d 100644
--- a/lib/activity.php
+++ b/lib/activity.php
@@ -83,6 +83,7 @@ class Activity
     const CREATOR = 'creator';
 
     const CONTENTNS = 'http://purl.org/rss/1.0/modules/content/';
+    const ENCODED = 'encoded';
 
     public $actor;   // an ActivityObject
     public $verb;    // a string (the URL)
@@ -268,14 +269,21 @@ class Activity
 
         $this->title = ActivityUtils::childContent($item, ActivityObject::TITLE, self::RSS);
 
-        $contentEl = ActivityUtils::child($item, ActivityUtils::CONTENT, self::CONTENTNS);
+        $contentEl = ActivityUtils::child($item, self::ENCODED, self::CONTENTNS);
 
         if (!empty($contentEl)) {
-            $this->content = htmlspecialchars_decode($contentEl->textContent, ENT_QUOTES);
+            // <content:encoded> XML node's text content is HTML; no further processing needed.
+            $this->content = $contentEl->textContent;
         } else {
             $descriptionEl = ActivityUtils::child($item, self::DESCRIPTION, self::RSS);
             if (!empty($descriptionEl)) {
-                $this->content = htmlspecialchars_decode($descriptionEl->textContent, ENT_QUOTES);
+                // Per spec, <description> must be plaintext.
+                // In practice, often there's HTML... but these days good
+                // feeds are using <content:encoded> which is explicitly
+                // real HTML.
+                // We'll treat this following spec, and do HTML escaping
+                // to convert from plaintext to HTML.
+                $this->content = htmlspecialchars($descriptionEl->textContent);
             }
         }
 
diff --git a/lib/activityutils.php b/lib/activityutils.php
index a7e99fb11..401fd7fc2 100644
--- a/lib/activityutils.php
+++ b/lib/activityutils.php
@@ -213,11 +213,19 @@ class ActivityUtils
         // slavishly following http://atompub.org/rfc4287.html#rfc.section.4.1.3.3
 
         if (empty($type) || $type == 'text') {
-            return $el->textContent;
+            // We have plaintext saved as the XML text content.
+            // Since we want HTML, we need to escape any special chars.
+            return htmlspecialchars($el->textContent);
         } else if ($type == 'html') {
+            // We have HTML saved as the XML text content.
+            // No additional processing required once we've got it.
             $text = $el->textContent;
-            return htmlspecialchars_decode($text, ENT_QUOTES);
+            return $text;
         } else if ($type == 'xhtml') {
+            // Per spec, the <content type="xhtml"> contains a single
+            // HTML <div> with XHTML namespace on it as a child node.
+            // We need to pull all of that <div>'s child nodes and
+            // serialize them back to an (X)HTML source fragment.
             $divEl = ActivityUtils::child($el, 'div', 'http://www.w3.org/1999/xhtml');
             if (empty($divEl)) {
                 return null;