diff -r 000000000000 -r 6474c204b198 intl/uconv/tests/unit/test_bug399284.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/intl/uconv/tests/unit/test_bug399284.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+function run_test()
+{
+    var failures = false;
+    var ccManager =
+	Components.classes["@mozilla.org/charset-converter-manager;1"]
+	.getService(Components.interfaces.nsICharsetConverterManager);
+
+    var decoderList = ccManager.getDecoderList();
+    while (decoderList.hasMore()) {
+	var decoder = decoderList.getNext();
+	try {
+	    var langGroup = ccManager.getCharsetLangGroupRaw(decoder);
+	} catch(e) {
+	    dump("no langGroup for " + decoder + "\n");
+	    failures = true;
+	}
+    }
+    if (failures) {
+	do_throw("missing langGroups");
+    }
+}