diff -r 000000000000 -r 6474c204b198 docshell/test/browser/browser_loadURI.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/docshell/test/browser/browser_loadURI.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,45 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+const gPostData = "postdata=true";
+
+function test() {
+  waitForExplicitFinish();
+
+  let tab = gBrowser.selectedTab = gBrowser.addTab();
+  registerCleanupFunction(function () {
+    gBrowser.removeTab(tab);
+  });
+
+  var dataStream = Cc["@mozilla.org/io/string-input-stream;1"].
+                   createInstance(Ci.nsIStringInputStream);
+  dataStream.data = gPostData;
+
+  var postStream = Cc["@mozilla.org/network/mime-input-stream;1"].
+                   createInstance(Ci.nsIMIMEInputStream);
+  postStream.addHeader("Content-Type", "application/x-www-form-urlencoded");
+  postStream.addContentLength = true;
+  postStream.setData(dataStream);
+
+  tab.linkedBrowser.loadURIWithFlags("http://mochi.test:8888/browser/docshell/test/browser/print_postdata.sjs", 0, null, null, postStream);
+  onTabLoad(tab, function (doc) {
+    var bodyText = doc.body.textContent;
+    is(bodyText, gPostData, "post data was submitted correctly");
+    finish();
+  });
+}
+
+function onTabLoad(tab, cb) {
+  tab.linkedBrowser.addEventListener("load", function listener(event) {
+    if (event.originalTarget != tab.linkedBrowser.contentDocument ||
+        event.target.location.href == "about:blank") {
+      info("skipping spurious load event");
+      return;
+    }
+    tab.linkedBrowser.removeEventListener("load", listener, true);
+    cb(tab.linkedBrowser.contentDocument);
+  }, true);
+}