From 620f28acc0699b4cf7b1b90c5125154d12665dd5 Mon Sep 17 00:00:00 2001
From: Jonathan Kew <jkew@mozilla.com>
Date: Wed, 17 Jul 2013 12:53:38 +0100
Subject: [PATCH] bug 879963 - test for redundant downloading of a repeated
 @font-face resource. r=dbaron

---
 layout/style/test/Makefile.in                 |   2 +
 layout/style/test/redundant_font_download.sjs |  60 ++++++++
 .../test/test_redundant_font_download.html    | 130 ++++++++++++++++++
 3 files changed, 192 insertions(+)
 create mode 100644 layout/style/test/redundant_font_download.sjs
 create mode 100644 layout/style/test/test_redundant_font_download.html

diff --git a/layout/style/test/Makefile.in b/layout/style/test/Makefile.in
index 76ba4defd91..f5f783b748f 100644
--- a/layout/style/test/Makefile.in
+++ b/layout/style/test/Makefile.in
@@ -145,6 +145,8 @@ MOCHITEST_FILES =	test_acid3_test46.html \
 		test_property_database.html \
 		test_priority_preservation.html \
 		test_property_syntax_errors.html \
+		test_redundant_font_download.html \
+		redundant_font_download.sjs \
 		test_rem_unit.html \
 		test_rule_insertion.html \
 		test_rule_serialization.html \
diff --git a/layout/style/test/redundant_font_download.sjs b/layout/style/test/redundant_font_download.sjs
new file mode 100644
index 00000000000..7eb7d8f8df5
--- /dev/null
+++ b/layout/style/test/redundant_font_download.sjs
@@ -0,0 +1,60 @@
+const BinaryOutputStream =
+  Components.Constructor("@mozilla.org/binaryoutputstream;1",
+                         "nsIBinaryOutputStream",
+                         "setOutputStream");
+
+// this is simply a hex dump of a red square .PNG image
+const RED_SQUARE =
+  [
+    0x89,  0x50,  0x4E,  0x47,  0x0D,  0x0A,  0x1A,  0x0A,  0x00,  0x00,
+    0x00,  0x0D,  0x49,  0x48,  0x44,  0x52,  0x00,  0x00,  0x00,  0x20,
+    0x00,  0x00,  0x00,  0x20,  0x08,  0x02,  0x00,  0x00,  0x00,  0xFC,
+    0x18,  0xED,  0xA3,  0x00,  0x00,  0x00,  0x01,  0x73,  0x52,  0x47,
+    0x42,  0x00,  0xAE,  0xCE,  0x1C,  0xE9,  0x00,  0x00,  0x00,  0x28,
+    0x49,  0x44,  0x41,  0x54,  0x48,  0xC7,  0xED,  0xCD,  0x41,  0x0D,
+    0x00,  0x00,  0x08,  0x04,  0xA0,  0xD3,  0xFE,  0x9D,  0x35,  0x85,
+    0x0F,  0x37,  0x28,  0x40,  0x4D,  0x6E,  0x75,  0x04,  0x02,  0x81,
+    0x40,  0x20,  0x10,  0x08,  0x04,  0x02,  0xC1,  0x93,  0x60,  0x01,
+    0xA3,  0xC4,  0x01,  0x3F,  0x58,  0x1D,  0xEF,  0x27,  0x00,  0x00,
+    0x00,  0x00,  0x49,  0x45,  0x4E,  0x44,  0xAE,  0x42,  0x60,  0x82
+  ];
+
+function handleRequest(request, response)
+{
+  var query = {};
+  request.queryString.split('&').forEach(function (val) {
+    var [name, value] = val.split('=');
+    query[name] = unescape(value);
+  });
+
+  response.setHeader("Cache-Control", "no-cache");
+
+  response.setStatusLine(request.httpVersion, 200, "OK");
+  response.setHeader("Content-Type", "text/plain", false);
+
+  var log = getState("bug-879963-request-log") || "";
+
+  var stream = new BinaryOutputStream(response.bodyOutputStream);
+
+  if (query["q"] == "init") {
+    log = "init"; // initialize the log, and return a PNG image
+    response.setHeader("Content-Type", "image/png", false);
+    stream.writeByteArray(RED_SQUARE, RED_SQUARE.length);
+  } else if (query["q"] == "image") {
+    log = log + ";" + query["q"];
+    response.setHeader("Content-Type", "image/png", false);
+    stream.writeByteArray(RED_SQUARE, RED_SQUARE.length);
+  } else if (query["q"] == "font") {
+    log = log + ";" + query["q"];
+    // we don't provide a real font; that's ok, OTS will just reject it
+    response.write("Junk");
+  } else if (query["q"] == "report") {
+    // don't include the actual "report" request in the log we return
+    response.write(log);
+  } else {
+    log = log + ";" + query["q"];
+    response.setStatusLine(request.httpVersion, 404, "Not Found");
+  }
+
+  setState("bug-879963-request-log", log);
+}
diff --git a/layout/style/test/test_redundant_font_download.html b/layout/style/test/test_redundant_font_download.html
new file mode 100644
index 00000000000..8349d692b29
--- /dev/null
+++ b/layout/style/test/test_redundant_font_download.html
@@ -0,0 +1,130 @@
+<!DOCTYPE HTML>
+<html>
+<!-- https://bugzilla.mozilla.org/show_bug.cgi?id=879963 -->
+<head>
+  <meta charset="utf-8">
+  <title>Test for bug 879963</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+
+<body>
+  <!-- Two <style> elements with identical @font-face rules.
+       Although multiple @font-face at-rules for the same family are legal,
+       and add faces to the family, we should NOT download the same resource
+       twice just because we have a duplicate face entry. -->
+  <style type="text/css">
+    @font-face {
+      font-family: foo;
+      src: url("redundant_font_download.sjs?q=font");
+    }
+    .test {
+      font-family: foo;
+    }
+  </style>
+
+  <style type="text/css">
+    @font-face {
+      font-family: foo;
+      src: url("redundant_font_download.sjs?q=font");
+    }
+    .test {
+      font-family: foo;
+    }
+  </style>
+
+  <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=879963">Mozilla Bug 879963</a>
+
+  <div>
+    <!-- the 'init' request returns an image (just so we can see it's working)
+         and initializes the request logging in our sjs server -->
+    <img src="redundant_font_download.sjs?q=init">
+  </div>
+
+  <div id="test">
+    Test
+  </div>
+
+  <div>
+    <img id="image2" src="">
+  </div>
+
+  <script type="application/javascript">
+    // helper to retrieve the server's request log as text
+    function getRequestLog() {
+      var xmlHttp = new XMLHttpRequest();
+      xmlHttp.open("GET", "redundant_font_download.sjs?q=report", false);
+      xmlHttp.send(null);
+      return xmlHttp.responseText;
+    }
+
+    // retrieve just the most recent request the server has seen
+    function getLastRequest() {
+      return getRequestLog().split(";").pop();
+    }
+
+    // poll the server at intervals of 'delay' ms until it has seen a specific request,
+    // or until maxTime ms have passed
+    function waitForRequest(request, delay, maxTime, func) {
+      timeLimit = Date.now() + maxTime;
+      var intervalId = window.setInterval(function() {
+        var req = getLastRequest();
+        if (req == request || Date.now() > timeLimit) {
+          window.clearInterval(intervalId);
+          func();
+        }
+      }.bind(this), delay);
+    }
+
+    // initially disable the second of the <style> elements,
+    // so we only have a single copy of the font-face
+    document.getElementsByTagName("style")[1].disabled = true;
+
+    SimpleTest.waitForExplicitFinish();
+
+    // We perform a series of actions that trigger requests to the .sjs server,
+    // and poll the server's request log at each stage to check that it has
+    // seen the request we expected before we proceed to the next step.
+    function startTest() {
+      is(getRequestLog(), "init", "request log has been initialized");
+
+      // this should trigger a font download
+      document.getElementById("test").className = "test";
+
+      // wait to confirm that the server has received the request
+      waitForRequest("font", 10, 5000, continueTest1);
+    }
+
+    function continueTest1() {
+      is(getRequestLog(), "init;font", "server received font request");
+
+      // trigger a request for the second image, to provide an explicit
+      // delimiter in the log before we enable the second @font-face rule
+      document.getElementById("image2").src = "redundant_font_download.sjs?q=image";
+
+      waitForRequest("image", 10, 5000, continueTest2);
+    }
+
+    function continueTest2() {
+      is(getRequestLog(), "init;font;image", "server received image request");
+
+      // enable the second <style> element: we should NOT see a second font request,
+      // we expect waitForRequest to time out instead
+      document.getElementsByTagName("style")[1].disabled = false;
+
+      waitForRequest("font", 10, 1000, continueTest3);
+    }
+
+    function continueTest3() {
+      is(getRequestLog(), "init;font;image", "should NOT have re-requested the font");
+
+      SimpleTest.finish();
+    }
+
+    waitForRequest("init", 10, 5000, startTest);
+
+  </script>
+
+</body>
+
+</html>