merge -r1221:1222 from branch 1.6 to trunk (bug 339)

git-svn-id: http://piwigo.org/svn/trunk@1223 68402e56-0260-453c-a942-63ccdbb3a9ee

admin/include/functions_metadata.php

@@ -53,6 +53,16 @@ function get_sync_iptc_data($file)
     // official keywords separator is the comma
     $iptc['keywords'] = preg_replace('/[.;]/', ',', $iptc['keywords']);
     $iptc['keywords'] = preg_replace('/^,+|,+$/', '', $iptc['keywords']);
+
+    $iptc['keywords'] = implode(
+      ',',
+      array_unique(
+        explode(
+          ',',
+          $iptc['keywords']
+          )
+        )
+      );
   }
 
   return $iptc;