diff -r 000000000000 -r 6474c204b198 parser/xml/test/unit/test_xml_declaration.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parser/xml/test/unit/test_xml_declaration.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,82 @@
+function noop() {}
+
+function run_test() {
+  var evts;
+
+  var contentHandler = {
+    attrs: null,
+    startDocument: function() {
+      evts.push("startDocument");
+    },
+    endDocument: noop,
+
+    startElement: function startElement() {
+      evts.push("startElement");
+    },
+
+    endElement: noop,
+    characters: noop,
+    processingInstruction: noop,
+    ignorableWhitespace: noop,
+    startPrefixMapping: noop,
+    endPrefixMapping: noop
+  };
+
+  function XMLDeclHandler(version, encoding, standalone) {
+    evts.splice(evts.length, 0, version, encoding, standalone);
+  }
+
+  const nsISAXXMLReader = Components.interfaces.nsISAXXMLReader;
+  var saxReader = Components.classes["@mozilla.org/saxparser/xmlreader;1"]
+                            .createInstance(nsISAXXMLReader);
+  saxReader.contentHandler = contentHandler;
+  saxReader.declarationHandler = XMLDeclHandler;
+
+  evts = [];
+  saxReader.parseFromString("<root/>", "application/xml");
+  do_check_eq(evts.length, 2);
+  do_check_eq(evts[0], "startDocument");
+  do_check_eq(evts[1], "startElement");
+
+  evts = [];
+  saxReader.parseFromString("<?xml version='1.0'?><root/>", "application/xml");
+  do_check_eq(evts.length, 5);
+  do_check_eq(evts[0], "startDocument");
+  do_check_eq(evts[1], "1.0");
+  do_check_eq(evts[2], "");
+  do_check_false(evts[3]);
+  do_check_eq(evts[4], "startElement");
+
+  evts = [];
+  saxReader.parseFromString("<?xml version='1.0' encoding='UTF-8'?><root/>", "application/xml");
+  do_check_eq(evts.length, 5);
+  do_check_eq(evts[0], "startDocument");
+  do_check_eq(evts[1], "1.0");
+  do_check_eq(evts[2], "UTF-8");
+  do_check_false(evts[3]);
+  do_check_eq(evts[4], "startElement");
+
+  evts = [];
+  saxReader.parseFromString("<?xml version='1.0' standalone='yes'?><root/>", "application/xml");
+  do_check_eq(evts.length, 5);
+  do_check_eq(evts[0], "startDocument");
+  do_check_eq(evts[1], "1.0");
+  do_check_eq(evts[2], "");
+  do_check_true(evts[3]);
+  do_check_eq(evts[4], "startElement");
+
+  evts = [];
+  saxReader.parseFromString("<?xml version='1.0' encoding='UTF-8' standalone='yes'?><root/>", "application/xml");
+  do_check_eq(evts.length, 5);
+  do_check_eq(evts[0], "startDocument");
+  do_check_eq(evts[1], "1.0");
+  do_check_eq(evts[2], "UTF-8");
+  do_check_true(evts[3]);
+  do_check_eq(evts[4], "startElement");
+
+  evts = [];
+  // Not well-formed
+  saxReader.parseFromString("<?xml encoding='UTF-8'?><root/>", "application/xml");
+  do_check_eq(evts.length, 1);
+  do_check_eq(evts[0], "startDocument");  
+}