From f7a686456c8debd005b5ed7eb79797576cc48357 Mon Sep 17 00:00:00 2001
From: Daniel Holbert <dholbert@cs.stanford.edu>
Date: Fri, 27 May 2011 21:55:20 -0700
Subject: [PATCH] Bug 660066 patch 2: Prevent nsFileDataURI from QI'ing to
 nsSimpleURI. r=bz

---
 .../base/src/nsFileDataProtocolHandler.cpp    | 13 +++++-
 netwerk/test/unit/test_bug660066.js           | 43 +++++++++++++++++++
 netwerk/test/unit/xpcshell.ini                |  1 +
 3 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 netwerk/test/unit/test_bug660066.js

diff --git a/content/base/src/nsFileDataProtocolHandler.cpp b/content/base/src/nsFileDataProtocolHandler.cpp
index 394e702f33df..b0d06a51447f 100644
--- a/content/base/src/nsFileDataProtocolHandler.cpp
+++ b/content/base/src/nsFileDataProtocolHandler.cpp
@@ -161,12 +161,23 @@ public:
   nsCOMPtr<nsIPrincipal> mPrincipal;
 };
 
+static NS_DEFINE_CID(kThisSimpleURIImplementationCID,
+                     NS_THIS_SIMPLEURI_IMPLEMENTATION_CID);
+
 NS_IMPL_ADDREF_INHERITED(nsFileDataURI, nsSimpleURI)
 NS_IMPL_RELEASE_INHERITED(nsFileDataURI, nsSimpleURI)
+
 NS_INTERFACE_MAP_BEGIN(nsFileDataURI)
   NS_INTERFACE_MAP_ENTRY(nsIURIWithPrincipal)
   if (aIID.Equals(kFILEDATAURICID))
-      foundInterface = static_cast<nsIURI*>(this);
+    foundInterface = static_cast<nsIURI*>(this);
+  else if (aIID.Equals(kThisSimpleURIImplementationCID)) {
+    // Need to return explicitly here, because if we just set foundInterface
+    // to null the NS_INTERFACE_MAP_END_INHERITING will end up calling into
+    // nsSimplURI::QueryInterface and finding something for this CID.
+    *aInstancePtr = nsnull;
+    return NS_NOINTERFACE;
+  }
   else
 NS_INTERFACE_MAP_END_INHERITING(nsSimpleURI)
 
diff --git a/netwerk/test/unit/test_bug660066.js b/netwerk/test/unit/test_bug660066.js
new file mode 100644
index 000000000000..abfc391ddf29
--- /dev/null
+++ b/netwerk/test/unit/test_bug660066.js
@@ -0,0 +1,43 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+Components.utils.import("resource://gre/modules/NetUtil.jsm");
+const Ci = Components.interfaces;
+const SIMPLEURI_SPEC = "data:text/plain,hello world";
+const FILEDATA_SPEC = "moz-filedata:123456";
+
+function do_info(text, stack) {
+  if (!stack)
+    stack = Components.stack.caller;
+
+  dump( "\n" +
+       "TEST-INFO | " + stack.filename + " | [" + stack.name + " : " +
+       stack.lineNumber + "] " + text + "\n");
+}
+
+function do_check_uri_neq(uri1, uri2)
+{
+  do_info("Checking equality in forward direction...");
+  do_check_false(uri1.equals(uri2));
+  do_check_false(uri1.equalsExceptRef(uri2));
+
+  do_info("Checking equality in reverse direction...");
+  do_check_false(uri2.equals(uri1));
+  do_check_false(uri2.equalsExceptRef(uri1));
+}
+
+function run_test()
+{
+  var simpleURI = NetUtil.newURI(SIMPLEURI_SPEC);
+  var fileDataURI = NetUtil.newURI(FILEDATA_SPEC);
+
+  do_info("Checking that " + SIMPLEURI_SPEC + " != " + FILEDATA_SPEC);
+  do_check_uri_neq(simpleURI, fileDataURI);
+
+  do_info("Changing the nsSimpleURI spec to match the nsFileDataURI");
+  simpleURI.spec = FILEDATA_SPEC;
+
+  do_info("Verifying that .spec matches");
+  do_check_eq(simpleURI.spec, fileDataURI.spec);
+
+  do_info("Checking that nsSimpleURI != nsFileDataURI despite their .spec matching")
+  do_check_uri_neq(simpleURI, fileDataURI);
+}
diff --git a/netwerk/test/unit/xpcshell.ini b/netwerk/test/unit/xpcshell.ini
index 9d0387f15fbc..8e11bae64429 100644
--- a/netwerk/test/unit/xpcshell.ini
+++ b/netwerk/test/unit/xpcshell.ini
@@ -60,6 +60,7 @@ tail =
 [test_bug652761.js]
 [test_bug651100.js]
 [test_bug659569.js]
+[test_bug660066.js]
 [test_cacheflags.js]
 [test_channel_close.js]
 [test_compareURIs.js]