diff --git a/parser/html/nsHtml5StreamParser.cpp b/parser/html/nsHtml5StreamParser.cpp
index 9f511983936e..ebece6ca64ec 100644
--- a/parser/html/nsHtml5StreamParser.cpp
+++ b/parser/html/nsHtml5StreamParser.cpp
@@ -992,6 +992,13 @@ nsHtml5StreamParser::ContinueAfterScripts(nsHtml5Tokenizer* aTokenizer,
       mSpeculations.RemoveElementAt(0);
       if (mSpeculations.IsEmpty()) {
         // yes, it was still the only speculation. Now stop speculating
+        if (mTreeBuilder->IsDiscretionaryFlushSafe()) {
+          // However, before telling the executor to read from stage, flush
+          // any pending ops straight to the executor, because otherwise
+          // they remain unflushed until we get more data from the network.
+          mTreeBuilder->SetOpSink(mExecutor);
+          mTreeBuilder->Flush();
+        }
         mTreeBuilder->SetOpSink(mExecutor->GetStage());
         mExecutor->StartReadingFromStage();
         mSpeculating = PR_FALSE;
diff --git a/parser/htmlparser/tests/mochitest/Makefile.in b/parser/htmlparser/tests/mochitest/Makefile.in
index 9bc8270947b0..9f93acdc4d94 100644
--- a/parser/htmlparser/tests/mochitest/Makefile.in
+++ b/parser/htmlparser/tests/mochitest/Makefile.in
@@ -62,6 +62,9 @@ _TEST_FILES =	parser_datreader.js \
 		test_bug566879.html \
 		test_compatmode.html \
 		invalidchar.xml \
+		test_bug568470.html \
+		file_bug568470.sjs \
+		file_bug568470-script.sjs \
 		$(NULL)
 
 libs:: $(_TEST_FILES)
diff --git a/parser/htmlparser/tests/mochitest/file_bug568470-script.sjs b/parser/htmlparser/tests/mochitest/file_bug568470-script.sjs
new file mode 100644
index 000000000000..6ba6ff08a6b1
--- /dev/null
+++ b/parser/htmlparser/tests/mochitest/file_bug568470-script.sjs
@@ -0,0 +1,14 @@
+function handleRequest(request, response)
+{
+  response.setHeader("Cache-Control", "no-cache", false);
+  response.setHeader("Content-Type", "text/javascript", false);
+  response.write("var i = 0;");
+  response.bodyOutputStream.flush();
+  response.processAsync();
+  var timer = Components.classes["@mozilla.org/timer;1"]
+    .createInstance(Components.interfaces.nsITimer);
+  timer.initWithCallback(function() {
+      response.finish();
+    }, 500, Components.interfaces.nsITimer.TYPE_ONE_SHOT);
+}
+
diff --git a/parser/htmlparser/tests/mochitest/file_bug568470.sjs b/parser/htmlparser/tests/mochitest/file_bug568470.sjs
new file mode 100644
index 000000000000..2a5b7d8deaf8
--- /dev/null
+++ b/parser/htmlparser/tests/mochitest/file_bug568470.sjs
@@ -0,0 +1,19 @@
+function handleRequest(request, response)
+{
+  response.setHeader("Cache-Control", "no-cache", false);
+  response.setHeader("Content-Type", "text/html", false);
+  response.write("<script src='file_bug568470-script.sjs'></script>");
+  response.write("<div id='flushable'>");
+  for (var i = 0; i < 2000; i++) { 
+    response.write("Lorem ipsum dolor sit amet. ");
+  }
+  response.write("</div>");
+  response.bodyOutputStream.flush();
+  response.processAsync();
+  var timer = Components.classes["@mozilla.org/timer;1"]
+    .createInstance(Components.interfaces.nsITimer);
+  timer.initWithCallback(function() {
+      response.finish();
+    }, 1200, Components.interfaces.nsITimer.TYPE_ONE_SHOT);
+}
+
diff --git a/parser/htmlparser/tests/mochitest/test_bug568470.html b/parser/htmlparser/tests/mochitest/test_bug568470.html
new file mode 100644
index 000000000000..f25059f11adb
--- /dev/null
+++ b/parser/htmlparser/tests/mochitest/test_bug568470.html
@@ -0,0 +1,51 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=568470
+-->
+<head>
+  <title>Test for Bug 568470</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=568470">Mozilla Bug 568470</a>
+<p id="display"></p>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+/** Test for Bug 568470 **/
+SimpleTest.waitForExplicitFinish();
+
+// assuming the test runs in less than a year...
+var time = new Date().getTime() + 1000*60*60*24*365;
+
+var interval = setInterval(function() {
+  var iframe = document.getElementsByTagName("iframe")[0];
+  if (iframe) {
+    var doc = iframe.contentDocument;
+    if (doc) {
+      if (doc.getElementById("flushable")) {
+        time = new Date();
+        clearInterval(interval);        
+      }
+    }
+  }
+}, 50);
+
+function finish() {
+  clearInterval(interval);
+  var elapsed = new Date().getTime() - time;
+  ok(elapsed > 400,
+     "Content flush time and parse end time not enough apart.");
+  SimpleTest.finish();
+}
+
+</script>
+</pre>
+<div id="content" style="display: none">
+  <iframe onload="finish();" src="file_bug568470.sjs"></iframe>
+</div>
+</body>
+</html>
+
