From 19f3323d773c47f404c789a4ea0be937ad55d013 Mon Sep 17 00:00:00 2001
From: "bzbarsky%mit.edu"
 <bzbarsky%mit.edu@18797224-902f-48f8-a5cc-f745e15eee43>
Date: Tue, 23 Oct 2007 21:56:43 +0000
Subject: [PATCH] Make the "href" property of stylesheets reflect the original
 URI that was reflected to load the sheet.  Bug 397427, r=dbaron,biesi,
 sr=dbaron, a=dsicore

git-svn-id: svn://10.0.0.236/trunk@238046 18797224-902f-48f8-a5cc-f745e15eee43
---
 mozilla/caps/src/nsScriptSecurityManager.cpp  |  9 +-
 mozilla/content/base/src/nsDocument.cpp       |  8 +-
 .../xul/document/src/nsXULDocument.cpp        | 14 +--
 mozilla/docshell/base/nsDocShell.cpp          |  7 +-
 mozilla/layout/base/nsPresShell.cpp           |  2 +-
 .../layout/mathml/base/src/nsMathMLFrame.cpp  |  2 +-
 mozilla/layout/style/nsCSSLoader.cpp          | 29 +++---
 mozilla/layout/style/nsCSSParser.cpp          |  2 +-
 mozilla/layout/style/nsCSSStyleSheet.cpp      | 17 ++--
 mozilla/layout/style/nsCSSStyleSheet.h        |  4 +-
 mozilla/layout/style/nsICSSStyleSheet.h       |  9 +-
 mozilla/layout/style/test/Makefile.in         | 10 ++
 mozilla/layout/style/test/post-redirect-1.css |  1 +
 mozilla/layout/style/test/post-redirect-2.css |  1 +
 mozilla/layout/style/test/post-redirect-3.css |  1 +
 .../layout/style/test/redirect-1.css^headers^ |  2 +
 .../layout/style/test/redirect-2.css^headers^ |  2 +
 .../layout/style/test/redirect-3.css^headers^ |  2 +
 mozilla/layout/style/test/test_bug397427.html | 92 +++++++++++++++++++
 mozilla/netwerk/base/public/nsNetUtil.h       | 22 +++++
 20 files changed, 176 insertions(+), 60 deletions(-)
 create mode 100644 mozilla/layout/style/test/post-redirect-1.css
 create mode 100644 mozilla/layout/style/test/post-redirect-2.css
 create mode 100644 mozilla/layout/style/test/post-redirect-3.css
 create mode 100644 mozilla/layout/style/test/redirect-1.css^headers^
 create mode 100644 mozilla/layout/style/test/redirect-2.css^headers^
 create mode 100644 mozilla/layout/style/test/redirect-3.css^headers^
 create mode 100644 mozilla/layout/style/test/test_bug397427.html

diff --git a/mozilla/caps/src/nsScriptSecurityManager.cpp b/mozilla/caps/src/nsScriptSecurityManager.cpp
index 77141739661..11effe6ccb1 100644
--- a/mozilla/caps/src/nsScriptSecurityManager.cpp
+++ b/mozilla/caps/src/nsScriptSecurityManager.cpp
@@ -446,13 +446,8 @@ nsScriptSecurityManager::GetChannelPrincipal(nsIChannel* aChannel,
     // OK, get the principal from the URI.  Make sure this does the same thing
     // as nsDocument::Reset and nsXULDocument::StartDocumentLoad.
     nsCOMPtr<nsIURI> uri;
-    nsLoadFlags loadFlags = 0;
-    nsresult rv = aChannel->GetLoadFlags(&loadFlags);
-    if (NS_SUCCEEDED(rv) && (loadFlags & nsIChannel::LOAD_REPLACE)) {
-      aChannel->GetURI(getter_AddRefs(uri));
-    } else {
-      aChannel->GetOriginalURI(getter_AddRefs(uri));
-    }
+    nsresult rv = NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
+    NS_ENSURE_SUCCESS(rv, rv);
 
     return GetCodebasePrincipal(uri, aPrincipal);
 }
diff --git a/mozilla/content/base/src/nsDocument.cpp b/mozilla/content/base/src/nsDocument.cpp
index 300f44fda70..4567ccb8351 100644
--- a/mozilla/content/base/src/nsDocument.cpp
+++ b/mozilla/content/base/src/nsDocument.cpp
@@ -1161,13 +1161,7 @@ nsDocument::Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup)
     // Note: this code is duplicated in nsXULDocument::StartDocumentLoad and
     // nsScriptSecurityManager::GetChannelPrincipal.    
     // Note: this should match nsDocShell::OnLoadingSite
-    nsLoadFlags loadFlags = 0;
-    nsresult rv = aChannel->GetLoadFlags(&loadFlags);
-    if (NS_SUCCEEDED(rv) && (loadFlags & nsIChannel::LOAD_REPLACE)) {
-      aChannel->GetURI(getter_AddRefs(uri));
-    } else {
-      aChannel->GetOriginalURI(getter_AddRefs(uri));
-    }
+    NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
 
     nsIScriptSecurityManager *securityManager =
       nsContentUtils::GetSecurityManager();
diff --git a/mozilla/content/xul/document/src/nsXULDocument.cpp b/mozilla/content/xul/document/src/nsXULDocument.cpp
index 06eed0050f3..c8c0548bdb1 100644
--- a/mozilla/content/xul/document/src/nsXULDocument.cpp
+++ b/mozilla/content/xul/document/src/nsXULDocument.cpp
@@ -424,18 +424,8 @@ nsXULDocument::StartDocumentLoad(const char* aCommand, nsIChannel* aChannel,
     mChannel = aChannel;
 
     // Get the URI.  Note that this should match nsDocShell::OnLoadingSite
-    // XXXbz this code is repeated from nsDocument::Reset and
-    // nsScriptSecurityManager::GetChannelPrincipal; we really need to refactor
-    // this part better.
-    nsLoadFlags loadFlags = 0;
-    nsresult rv = aChannel->GetLoadFlags(&loadFlags);
-    if (NS_SUCCEEDED(rv)) {
-        if (loadFlags & nsIChannel::LOAD_REPLACE) {
-            rv = aChannel->GetURI(getter_AddRefs(mDocumentURI));
-        } else {
-            rv = aChannel->GetOriginalURI(getter_AddRefs(mDocumentURI));
-        }
-    }
+    nsresult rv =
+        NS_GetFinalChannelURI(aChannel, getter_AddRefs(mDocumentURI));
     NS_ENSURE_SUCCESS(rv, rv);
     
     rv = ResetStylesheetsToURI(mDocumentURI);
diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index 8c07f26b6c2..9e0c5e4fa6e 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -7760,12 +7760,7 @@ nsDocShell::OnLoadingSite(nsIChannel * aChannel, PRBool aFireOnLocationChange,
     // else use the original url
     //
     // Note that this should match what documents do (see nsDocument::Reset).
-    nsLoadFlags loadFlags = 0;
-    aChannel->GetLoadFlags(&loadFlags);
-    if (loadFlags & nsIChannel::LOAD_REPLACE)
-        aChannel->GetURI(getter_AddRefs(uri));
-    else
-        aChannel->GetOriginalURI(getter_AddRefs(uri));
+    NS_GetFinalChannelURI(aChannel, getter_AddRefs(uri));
     NS_ENSURE_TRUE(uri, PR_FALSE);
 
     return OnNewURI(uri, aChannel, mLoadType, aFireOnLocationChange,
diff --git a/mozilla/layout/base/nsPresShell.cpp b/mozilla/layout/base/nsPresShell.cpp
index e4e5c672367..7f2470f3747 100644
--- a/mozilla/layout/base/nsPresShell.cpp
+++ b/mozilla/layout/base/nsPresShell.cpp
@@ -1849,7 +1849,7 @@ nsresult PresShell::CreatePreferenceStyleSheet(void)
     result = NS_NewURI(getter_AddRefs(uri), "about:PreferenceStyleSheet", nsnull);
     if (NS_SUCCEEDED(result)) {
       NS_ASSERTION(uri, "null but no error");
-      result = mPrefStyleSheet->SetURIs(uri, uri);
+      result = mPrefStyleSheet->SetURIs(uri, nsnull, uri);
       if (NS_SUCCEEDED(result)) {
         mPrefStyleSheet->SetComplete();
         nsCOMPtr<nsIDOMCSSStyleSheet> sheet(do_QueryInterface(mPrefStyleSheet));
diff --git a/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp b/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp
index 9611a960bcf..6c6516c77e1 100644
--- a/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp
+++ b/mozilla/layout/mathml/base/src/nsMathMLFrame.cpp
@@ -594,7 +594,7 @@ GetMathMLAttributeStyleSheet(nsPresContext* aPresContext,
   nsCOMPtr<nsICSSStyleSheet> cssSheet(do_CreateInstance(kCSSStyleSheetCID));
   if (!cssSheet)
     return;
-  cssSheet->SetURIs(uri, uri);
+  cssSheet->SetURIs(uri, nsnull, uri);
   cssSheet->SetTitle(NS_ConvertASCIItoUTF16(kTitle));
   // all done, no further activity from the net involved, so we better do this
   cssSheet->SetComplete();
diff --git a/mozilla/layout/style/nsCSSLoader.cpp b/mozilla/layout/style/nsCSSLoader.cpp
index 55d0af68558..fb549ba616c 100644
--- a/mozilla/layout/style/nsCSSLoader.cpp
+++ b/mozilla/layout/style/nsCSSLoader.cpp
@@ -777,19 +777,18 @@ SheetLoadData::OnStreamComplete(nsIUnicharStreamLoader* aLoader,
     return NS_OK;
   }
   
-  nsCOMPtr<nsIURI> channelURI;
+  nsCOMPtr<nsIURI> originalURI;
+  channel->GetOriginalURI(getter_AddRefs(originalURI));
+
   // If the channel's original URI is "chrome:", we want that, since
   // the observer code in nsXULPrototypeCache depends on chrome stylesheets
   // having a chrome URI.  (Whether or not chrome stylesheets come through
   // this codepath seems nondeterministic.)
   // Otherwise we want the potentially-HTTP-redirected URI.
-  channel->GetOriginalURI(getter_AddRefs(channelURI));
-  PRBool isChrome;
-  if (NS_FAILED(channelURI->SchemeIs("chrome", &isChrome)) || !isChrome) {
-    channel->GetURI(getter_AddRefs(channelURI));
-  }
+  nsCOMPtr<nsIURI> channelURI;
+  NS_GetFinalChannelURI(channel, getter_AddRefs(channelURI));
 
-  if (!channelURI) {
+  if (!channelURI || !originalURI) {
     NS_ERROR("Someone just violated the nsIRequest contract");
     LOG_WARN(("  Channel without a URI.  Bad!"));
     mLoader->SheetComplete(this, NS_ERROR_UNEXPECTED);
@@ -875,9 +874,9 @@ SheetLoadData::OnStreamComplete(nsIUnicharStreamLoader* aLoader,
     return NS_OK;
   }    
 
-  // Enough to set the URI on mSheet, since any sibling datas we have share
+  // Enough to set the URIs on mSheet, since any sibling datas we have share
   // the same mInner as mSheet and will thus get the same URI.
-  mSheet->SetURIs(channelURI, channelURI);
+  mSheet->SetURIs(channelURI, originalURI, channelURI);
   
   PRBool completed;
   return mLoader->ParseSheet(aDataStream, this, completed);
@@ -1082,19 +1081,25 @@ CSSLoaderImpl::CreateSheet(nsIURI* aURI,
 
   if (!*aSheet) {
     aSheetState = eSheetNeedsParser;
-    nsIURI *sheetURI = aURI;
-    nsCOMPtr<nsIURI> baseURI = aURI;
+    nsIURI *sheetURI;
+    nsCOMPtr<nsIURI> baseURI;
+    nsIURI* originalURI;
     if (!aURI) {
       // Inline style.  Use the document's base URL so that @import in
       // the inline sheet picks up the right base.
       NS_ASSERTION(aLinkingContent, "Inline stylesheet without linking content?");
       baseURI = aLinkingContent->GetBaseURI();
       sheetURI = aLinkingContent->GetDocument()->GetDocumentURI();
+      originalURI = nsnull;
+    } else {
+      baseURI = aURI;
+      sheetURI = aURI;
+      originalURI = aURI;
     }
 
     rv = NS_NewCSSStyleSheet(aSheet);
     NS_ENSURE_SUCCESS(rv, rv);
-    (*aSheet)->SetURIs(sheetURI, baseURI);
+    (*aSheet)->SetURIs(sheetURI, originalURI, baseURI);
   }
 
   NS_ASSERTION(*aSheet, "We should have a sheet by now!");
diff --git a/mozilla/layout/style/nsCSSParser.cpp b/mozilla/layout/style/nsCSSParser.cpp
index 6afc9ebe843..a844d7462b9 100644
--- a/mozilla/layout/style/nsCSSParser.cpp
+++ b/mozilla/layout/style/nsCSSParser.cpp
@@ -707,7 +707,7 @@ CSSParserImpl::Parse(nsIUnicharInputStream* aInput,
     NS_NewCSSStyleSheet(getter_AddRefs(mSheet));
     NS_ENSURE_TRUE(mSheet, NS_ERROR_OUT_OF_MEMORY);
 
-    mSheet->SetURIs(aSheetURI, aBaseURI);
+    mSheet->SetURIs(aSheetURI, aSheetURI, aBaseURI);
     mSheet->SetPrincipal(aSheetPrincipal);
     mNameSpaceMap = nsnull;
   }
diff --git a/mozilla/layout/style/nsCSSStyleSheet.cpp b/mozilla/layout/style/nsCSSStyleSheet.cpp
index a2f458ff4f4..2dc36f89d5a 100644
--- a/mozilla/layout/style/nsCSSStyleSheet.cpp
+++ b/mozilla/layout/style/nsCSSStyleSheet.cpp
@@ -771,7 +771,8 @@ nsCSSStyleSheet::DropRuleProcessor(nsCSSRuleProcessor* aProcessor)
 
 
 NS_IMETHODIMP
-nsCSSStyleSheet::SetURIs(nsIURI* aSheetURI, nsIURI* aBaseURI)
+nsCSSStyleSheet::SetURIs(nsIURI* aSheetURI, nsIURI* aOriginalSheetURI,
+                         nsIURI* aBaseURI)
 {
   NS_PRECONDITION(aSheetURI && aBaseURI, "null ptr");
 
@@ -779,6 +780,7 @@ nsCSSStyleSheet::SetURIs(nsIURI* aSheetURI, nsIURI* aBaseURI)
                "Can't call SetURL on sheets that are complete or have rules");
 
   mInner->mSheetURI = aSheetURI;
+  mInner->mOriginalSheetURI = aOriginalSheetURI;
   mInner->mBaseURI = aBaseURI;
   return NS_OK;
 }
@@ -1416,15 +1418,14 @@ nsCSSStyleSheet::GetParentStyleSheet(nsIDOMStyleSheet** aParentStyleSheet)
 NS_IMETHODIMP
 nsCSSStyleSheet::GetHref(nsAString& aHref)
 {
-  nsCAutoString str;
-
-  // XXXldb The DOM spec says that this should be null for inline style sheets.
-  if (mInner->mSheetURI) {
-    mInner->mSheetURI->GetSpec(str);
+  if (mInner->mOriginalSheetURI) {
+    nsCAutoString str;
+    mInner->mOriginalSheetURI->GetSpec(str);
+    CopyUTF8toUTF16(str, aHref);
+  } else {
+    SetDOMStringToNull(aHref);
   }
 
-  CopyUTF8toUTF16(str, aHref);
-
   return NS_OK;
 }
 
diff --git a/mozilla/layout/style/nsCSSStyleSheet.h b/mozilla/layout/style/nsCSSStyleSheet.h
index 9179ceebf6c..9b72f99a6cc 100644
--- a/mozilla/layout/style/nsCSSStyleSheet.h
+++ b/mozilla/layout/style/nsCSSStyleSheet.h
@@ -74,6 +74,7 @@ public:
 
   nsAutoVoidArray        mSheets;
   nsCOMPtr<nsIURI>       mSheetURI; // for error reports, etc.
+  nsCOMPtr<nsIURI>       mOriginalSheetURI;  // for GetHref.  Can be null.
   nsCOMPtr<nsIURI>       mBaseURI; // for resolving relative URIs
   nsCOMPtr<nsIPrincipal> mPrincipal;
   nsCOMArray<nsICSSRule> mOrderedRules;
@@ -136,7 +137,8 @@ public:
   NS_IMETHOD ReplaceRuleInGroup(nsICSSGroupRule* aGroup, nsICSSRule* aOld, nsICSSRule* aNew);
   NS_IMETHOD StyleSheetCount(PRInt32& aCount) const;
   NS_IMETHOD GetStyleSheetAt(PRInt32 aIndex, nsICSSStyleSheet*& aSheet) const;
-  NS_IMETHOD SetURIs(nsIURI* aSheetURI, nsIURI* aBaseURI);
+  NS_IMETHOD SetURIs(nsIURI* aSheetURI, nsIURI* aOriginalSheetURI,
+                     nsIURI* aBaseURI);
   virtual NS_HIDDEN_(void) SetPrincipal(nsIPrincipal* aPrincipal);
   virtual NS_HIDDEN_(nsIPrincipal*) Principal() const;
   NS_IMETHOD SetTitle(const nsAString& aTitle);
diff --git a/mozilla/layout/style/nsICSSStyleSheet.h b/mozilla/layout/style/nsICSSStyleSheet.h
index 77df3fa9ed9..c38b8367a86 100644
--- a/mozilla/layout/style/nsICSSStyleSheet.h
+++ b/mozilla/layout/style/nsICSSStyleSheet.h
@@ -53,10 +53,10 @@ class nsICSSImportRule;
 class nsIPrincipal;
 
 // IID for the nsICSSStyleSheet interface
-// 36541c18-e735-48ef-8622-3a481275b757
+// 74fa10f3-fab7-425a-a7dd-e2afd1ba7a07
 #define NS_ICSS_STYLE_SHEET_IID     \
-{ 0x36541c18, 0xe735, 0x48ef, \
- { 0x86, 0x22, 0x3a, 0x48, 0x12, 0x75, 0xb7, 0x57 } }
+{ 0x74fa10f3, 0xfab7, 0x425a, \
+ { 0xa7, 0xdd, 0xe2, 0xaf, 0xd1, 0xba, 0x7a, 0x07 } }
 
 class nsICSSStyleSheet : public nsIStyleSheet {
 public:
@@ -87,7 +87,8 @@ public:
    * SetURIs may only be called while the sheet is 1) incomplete and 2)
    * has no rules in it
    */
-  NS_IMETHOD  SetURIs(nsIURI* aSheetURI, nsIURI* aBaseURI) = 0;
+  NS_IMETHOD  SetURIs(nsIURI* aSheetURI, nsIURI* aOriginalSheetURI,
+                      nsIURI* aBaseURI) = 0;
 
   /**
    * SetPrincipal should be called on all sheets before parsing into them.
diff --git a/mozilla/layout/style/test/Makefile.in b/mozilla/layout/style/test/Makefile.in
index 1ba18dfe432..69cb05eb679 100644
--- a/mozilla/layout/style/test/Makefile.in
+++ b/mozilla/layout/style/test/Makefile.in
@@ -83,6 +83,7 @@ _TEST_FILES =	test_bug74880.html \
 		test_bug389464.html \
 		test_bug391034.html \
 		test_bug391221.html \
+		test_bug397427.html \
 		test_compute_data_with_start_struct.html \
 		test_dont_use_document_colors.html \
 		test_inherit_storage.html \
@@ -101,6 +102,15 @@ _TEST_FILES =	test_bug74880.html \
 		unstyled.css \
 		unstyled-frame.xml \
 		unstyled-frame.css \
+		redirect-1.css \
+		post-redirect-1.css \
+		redirect-1.css^headers^ \
+		redirect-2.css \
+		post-redirect-2.css \
+		redirect-2.css^headers^ \
+		redirect-3.css \
+		redirect-3.css^headers^ \
+		post-redirect-3.css \
 		$(NULL)
 
 
diff --git a/mozilla/layout/style/test/post-redirect-1.css b/mozilla/layout/style/test/post-redirect-1.css
new file mode 100644
index 00000000000..c2ae5d6eb2c
--- /dev/null
+++ b/mozilla/layout/style/test/post-redirect-1.css
@@ -0,0 +1 @@
+#one { color: green; background: url("#"); }
diff --git a/mozilla/layout/style/test/post-redirect-2.css b/mozilla/layout/style/test/post-redirect-2.css
new file mode 100644
index 00000000000..0a75299ce2e
--- /dev/null
+++ b/mozilla/layout/style/test/post-redirect-2.css
@@ -0,0 +1 @@
+#two { color: green; background: url("#"); }
diff --git a/mozilla/layout/style/test/post-redirect-3.css b/mozilla/layout/style/test/post-redirect-3.css
new file mode 100644
index 00000000000..b33887ae32c
--- /dev/null
+++ b/mozilla/layout/style/test/post-redirect-3.css
@@ -0,0 +1 @@
+#three { color: green; background: url("#"); }
diff --git a/mozilla/layout/style/test/redirect-1.css^headers^ b/mozilla/layout/style/test/redirect-1.css^headers^
new file mode 100644
index 00000000000..582de3f2be2
--- /dev/null
+++ b/mozilla/layout/style/test/redirect-1.css^headers^
@@ -0,0 +1,2 @@
+HTTP 302 Found
+Location: http://example.org/tests/layout/style/test/post-redirect-1.css
diff --git a/mozilla/layout/style/test/redirect-2.css^headers^ b/mozilla/layout/style/test/redirect-2.css^headers^
new file mode 100644
index 00000000000..09280cc486b
--- /dev/null
+++ b/mozilla/layout/style/test/redirect-2.css^headers^
@@ -0,0 +1,2 @@
+HTTP 302 Found
+Location: http://example.org/tests/layout/style/test/post-redirect-2.css
diff --git a/mozilla/layout/style/test/redirect-3.css^headers^ b/mozilla/layout/style/test/redirect-3.css^headers^
new file mode 100644
index 00000000000..42419234f2d
--- /dev/null
+++ b/mozilla/layout/style/test/redirect-3.css^headers^
@@ -0,0 +1,2 @@
+HTTP 302 Found
+Location: http://example.org/tests/layout/style/test/post-redirect-3.css
diff --git a/mozilla/layout/style/test/test_bug397427.html b/mozilla/layout/style/test/test_bug397427.html
new file mode 100644
index 00000000000..ae457215e11
--- /dev/null
+++ b/mozilla/layout/style/test/test_bug397427.html
@@ -0,0 +1,92 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=397427
+-->
+<head>
+  <title>Test for Bug 397427</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" />
+  <style id="a">
+    @import url("redirect-1.css");
+    @import url("redirect-2.css");
+    .test { color: red }
+  </style>
+  <link id="b" rel="stylesheet" href="http://example.com">
+  <link id="c" rel="stylesheet" href="redirect-2.css">
+  <link id="d" rel="stylesheet" href="redirect-3.css">
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=397427">Mozilla Bug 397427</a>
+<p id="display">
+<span id="one" class="test"></span>
+<span id="two" class="test"></span>
+<span id="three" class="test"></span>
+</p>
+<div id="content" style="display: none">
+  
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+
+/** Test for Bug 397427 **/
+SimpleTest.waitForExplicitFinish();
+
+addLoadEvent(function() {
+  is($("a").sheet.href, null, "href should be null");
+  is(typeof($("a").sheet.href), "object", "should be actual null");
+
+  // Make sure the redirected sheets are loaded and have the right base URI
+  is(document.defaultView.getComputedStyle($("one"), "").color,
+     "rgb(0, 128, 0)", "Redirect 1 did not work");
+  is(document.defaultView.getComputedStyle($("one"), "").backgroundImage,
+     "url(http://example.org/tests/layout/style/test/post-redirect-1.css#)",
+      "Redirect 1 did not get right base URI");
+  is(document.defaultView.getComputedStyle($("two"), "").color,
+     "rgb(0, 128, 0)", "Redirect 2 did not work");
+  is(document.defaultView.getComputedStyle($("two"), "").backgroundImage,
+     "url(http://example.org/tests/layout/style/test/post-redirect-2.css#)",
+      "Redirect 2 did not get right base URI");
+  is(document.defaultView.getComputedStyle($("three"), "").color,
+     "rgb(0, 128, 0)", "Redirect 3 did not work");
+  is(document.defaultView.getComputedStyle($("three"), "").backgroundImage,
+     "url(http://example.org/tests/layout/style/test/post-redirect-3.css#)",
+      "Redirect 3 did not get right base URI");
+
+  var ruleList = $("a").sheet.cssRules;
+  
+  is(ruleList[0].styleSheet.href,
+     window.location.href.replace(/test_bug397427.html$/, "redirect-1.css"),
+     "Unexpected href for imported sheet");
+  todo(ruleList[0].href == window.location.href.replace(/test_bug397427.html$/, "redirect-1.css"),
+       "Rule href should be absolute");
+  is(ruleList[1].styleSheet.href,
+     window.location.href.replace(/test_bug397427.html$/, "redirect-2.css"),
+     "Unexpected href for imported sheet");
+  todo(ruleList[1].href == window.location.href.replace(/test_bug397427.html$/, "redirect-2.css"),
+       "Rule href should be absolute");
+
+  is($("b").href, "http://example.com/", "Unexpected href one");
+  is($("b").href, $("b").sheet.href,
+     "Should have the same href when not redirecing");
+
+  is($("c").href,
+     window.location.href.replace(/test_bug397427.html$/, "redirect-2.css"),
+     "Unexpected href two");
+  is($("c").href, $("c").sheet.href,
+     "Should have the same href when redirecting");
+     
+  is($("d").href,
+     window.location.href.replace(/test_bug397427.html$/, "redirect-3.css"),
+     "Unexpected href three");
+  is($("d").href, $("d").sheet.href,
+     "Should have the same href when redirecting again");
+})
+
+addLoadEvent(SimpleTest.finish);
+</script>
+</pre>
+</body>
+</html>
+
diff --git a/mozilla/netwerk/base/public/nsNetUtil.h b/mozilla/netwerk/base/public/nsNetUtil.h
index ce786fe4bce..5a159b53f71 100644
--- a/mozilla/netwerk/base/public/nsNetUtil.h
+++ b/mozilla/netwerk/base/public/nsNetUtil.h
@@ -1304,4 +1304,26 @@ NS_GetInnermostURI(nsIURI *uri)
     return uri;
 }
 
+/**
+ * Get the "final" URI for a channel.  This is either the same as GetURI or
+ * GetOriginalURI, depending on whether this channel has
+ * nsIChanel::LOAD_REPLACE set.  For channels without that flag set, the final
+ * URI is the original URI, while for ones with the flag the final URI is the
+ * channel URI.
+ */
+inline nsresult
+NS_GetFinalChannelURI(nsIChannel* channel, nsIURI** uri)
+{
+    *uri = nsnull;
+    nsLoadFlags loadFlags = 0;
+    nsresult rv = channel->GetLoadFlags(&loadFlags);
+    NS_ENSURE_SUCCESS(rv, rv);
+    
+    if (loadFlags & nsIChannel::LOAD_REPLACE) {
+        return channel->GetURI(uri);
+    }
+    
+    return channel->GetOriginalURI(uri);
+}
+
 #endif // !nsNetUtil_h__