1 files changed, 11 insertions, 0 deletions
diff --git a/lib/util.php b/lib/util.php
index fbef8764a..4a55cbfe5 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -496,6 +496,17 @@ function common_linkify($url) {
     }
 
     $attrs = array('href' => $longurl, 'rel' => 'external');
+
+// if this URL is an attachment, then we set class='attachment' and id='attahcment-ID'
+// where ID is the id of the attachment for the given URL.
+    $query = "select file_oembed.file_id as file_id from file join file_oembed on file.id = file_oembed.file_id where file.url='$longurl'";
+    $file = new File;
+    $file->query($query);
+    $file->fetch();
+    if (!empty($file->file_id)) {
+        $attrs['class'] = 'attachment';
+        $attrs['id'] = "attachment-{$file->file_id}";
+    }
     return XMLStringer::estring('a', $attrs, $display);
 }