The Tor Browser: content/base/src/nsScriptLoader.cpp@6474c204b198 (annotated)

content/base/src/nsScriptLoader.cpp@6474c204b198 (annotated)

content/base/src/nsScriptLoader.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 // vim: ft=cpp tw=78 sw=2 et ts=2
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  * A class that handles loading and evaluation of <script> elements.
  */
 #include "nsScriptLoader.h"
 #include "jsapi.h"
 #include "jsfriendapi.h"
 #include "nsIUnicodeDecoder.h"
 #include "nsIContent.h"
 #include "nsJSUtils.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/Element.h"
 #include "nsGkAtoms.h"
 #include "nsNetUtil.h"
 #include "nsIJSRuntimeService.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIScriptContext.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIPrincipal.h"
 #include "nsJSPrincipals.h"
 #include "nsContentPolicyUtils.h"
 #include "nsIHttpChannel.h"
 #include "nsIHttpChannelInternal.h"
 #include "nsITimedChannel.h"
 #include "nsIScriptElement.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "nsIDocShell.h"
 #include "nsContentUtils.h"
 #include "nsCxPusher.h"
 #include "nsUnicharUtils.h"
 #include "nsAutoPtr.h"
 #include "nsIXPConnect.h"
 #include "nsError.h"
 #include "nsThreadUtils.h"
 #include "nsDocShellCID.h"
 #include "nsIContentSecurityPolicy.h"
 #include "prlog.h"
 #include "nsIChannelPolicy.h"
 #include "nsChannelPolicy.h"
 #include "nsCRT.h"
 #include "nsContentCreatorFunctions.h"
 #include "nsCrossSiteListenerProxy.h"
 #include "nsSandboxFlags.h"
 #include "nsContentTypeParser.h"
 #include "nsINetworkSeer.h"
 #include "mozilla/dom/EncodingUtils.h"
 #include "mozilla/CORSMode.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/unused.h"
 #ifdef PR_LOGGING
 static PRLogModuleInfo* gCspPRLog;
 #endif
 using namespace mozilla;
 using namespace mozilla::dom;
 //////////////////////////////////////////////////////////////
 // Per-request data structure
 //////////////////////////////////////////////////////////////
 class nsScriptLoadRequest MOZ_FINAL : public nsISupports {
 public:
   nsScriptLoadRequest(nsIScriptElement* aElement,
                       uint32_t aVersion,
                       CORSMode aCORSMode)
     : mElement(aElement),
       mLoading(true),
       mIsInline(true),
       mHasSourceMapURL(false),
       mScriptTextBuf(nullptr),
       mScriptTextLength(0),
       mJSVersion(aVersion),
       mLineNo(1),
       mCORSMode(aCORSMode)
   {
   }
   ~nsScriptLoadRequest()
   {
     if (mScriptTextBuf) {
       js_free(mScriptTextBuf);
     }
   }
   NS_DECL_THREADSAFE_ISUPPORTS
   void FireScriptAvailable(nsresult aResult)
   {
     mElement->ScriptAvailable(aResult, mElement, mIsInline, mURI, mLineNo);
   }
   void FireScriptEvaluated(nsresult aResult)
   {
     mElement->ScriptEvaluated(aResult, mElement, mIsInline);
   }
   bool IsPreload()
   {
     return mElement == nullptr;
   }
   nsCOMPtr<nsIScriptElement> mElement;
   bool mLoading;          // Are we still waiting for a load to complete?
   bool mIsInline;         // Is the script inline or loaded?
   bool mHasSourceMapURL;  // Does the HTTP header have a source map url?
   nsString mSourceMapURL; // Holds source map url for loaded scripts
   jschar* mScriptTextBuf;   // Holds script text for non-inline scripts. Don't
   size_t mScriptTextLength; // use nsString so we can give ownership to jsapi.
   uint32_t mJSVersion;
   nsCOMPtr<nsIURI> mURI;
   nsCOMPtr<nsIPrincipal> mOriginPrincipal;
   nsAutoCString mURL;   // Keep the URI's filename alive during off thread parsing.
   int32_t mLineNo;
   const CORSMode mCORSMode;
 };
 // The nsScriptLoadRequest is passed as the context to necko, and thus
 // it needs to be threadsafe. Necko won't do anything with this
 // context, but it will AddRef and Release it on other threads.
 NS_IMPL_ISUPPORTS0(nsScriptLoadRequest)
 //////////////////////////////////////////////////////////////
 //
 //////////////////////////////////////////////////////////////
 nsScriptLoader::nsScriptLoader(nsIDocument *aDocument)
   : mDocument(aDocument),
     mBlockerCount(0),
     mEnabled(true),
     mDeferEnabled(false),
     mDocumentParsingDone(false),
     mBlockingDOMContentLoaded(false)
 {
   // enable logging for CSP
 #ifdef PR_LOGGING
   if (!gCspPRLog)
     gCspPRLog = PR_NewLogModule("CSP");
 #endif
 }
 nsScriptLoader::~nsScriptLoader()
 {
   mObservers.Clear();
   if (mParserBlockingRequest) {
     mParserBlockingRequest->FireScriptAvailable(NS_ERROR_ABORT);
   }
   for (uint32_t i = 0; i < mXSLTRequests.Length(); i++) {
     mXSLTRequests[i]->FireScriptAvailable(NS_ERROR_ABORT);
   }
   for (uint32_t i = 0; i < mDeferRequests.Length(); i++) {
     mDeferRequests[i]->FireScriptAvailable(NS_ERROR_ABORT);
   }
   for (uint32_t i = 0; i < mAsyncRequests.Length(); i++) {
     mAsyncRequests[i]->FireScriptAvailable(NS_ERROR_ABORT);
   }
   for (uint32_t i = 0; i < mNonAsyncExternalScriptInsertedRequests.Length(); i++) {
     mNonAsyncExternalScriptInsertedRequests[i]->FireScriptAvailable(NS_ERROR_ABORT);
   }
   // Unblock the kids, in case any of them moved to a different document
   // subtree in the meantime and therefore aren't actually going away.
   for (uint32_t j = 0; j < mPendingChildLoaders.Length(); ++j) {
     mPendingChildLoaders[j]->RemoveExecuteBlocker();
   }
 }
 NS_IMPL_ISUPPORTS(nsScriptLoader, nsIStreamLoaderObserver)
 // Helper method for checking if the script element is an event-handler
 // This means that it has both a for-attribute and a event-attribute.
 // Also, if the for-attribute has a value that matches "\s*window\s*",
 // and the event-attribute matches "\s*onload([ \(].*)?" then it isn't an
 // eventhandler. (both matches are case insensitive).
 // This is how IE seems to filter out a window's onload handler from a
 // <script for=... event=...> element.
 static bool
 IsScriptEventHandler(nsIContent* aScriptElement)
 {
   if (!aScriptElement->IsHTML()) {
     return false;
   }
   nsAutoString forAttr, eventAttr;
   if (!aScriptElement->GetAttr(kNameSpaceID_None, nsGkAtoms::_for, forAttr) ||
       !aScriptElement->GetAttr(kNameSpaceID_None, nsGkAtoms::event, eventAttr)) {
     return false;
   }
   const nsAString& for_str =
     nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(forAttr);
   if (!for_str.LowerCaseEqualsLiteral("window")) {
     return true;
   }
   // We found for="window", now check for event="onload".
   const nsAString& event_str =
     nsContentUtils::TrimWhitespace<nsCRT::IsAsciiSpace>(eventAttr, false);
   if (!StringBeginsWith(event_str, NS_LITERAL_STRING("onload"),
                         nsCaseInsensitiveStringComparator())) {
     // It ain't "onload.*".
     return true;
   }
   nsAutoString::const_iterator start, end;
   event_str.BeginReading(start);
   event_str.EndReading(end);
   start.advance(6); // advance past "onload"
   if (start != end && *start != '(' && *start != ' ') {
     // We got onload followed by something other than space or
     // '('. Not good enough.
     return true;
   }
   return false;
 }
 nsresult
 nsScriptLoader::CheckContentPolicy(nsIDocument* aDocument,
                                    nsISupports *aContext,
                                    nsIURI *aURI,
                                    const nsAString &aType)
 {
   int16_t shouldLoad = nsIContentPolicy::ACCEPT;
   nsresult rv = NS_CheckContentLoadPolicy(nsIContentPolicy::TYPE_SCRIPT,
                                           aURI,
                                           aDocument->NodePrincipal(),
                                           aContext,
                                           NS_LossyConvertUTF16toASCII(aType),
                                           nullptr,    //extra
                                           &shouldLoad,
                                           nsContentUtils::GetContentPolicy(),
                                           nsContentUtils::GetSecurityManager());
   if (NS_FAILED(rv) || NS_CP_REJECTED(shouldLoad)) {
     if (NS_FAILED(rv) || shouldLoad != nsIContentPolicy::REJECT_TYPE) {
       return NS_ERROR_CONTENT_BLOCKED;
     }
     return NS_ERROR_CONTENT_BLOCKED_SHOW_ALT;
   }
   return NS_OK;
 }
 nsresult
 nsScriptLoader::ShouldLoadScript(nsIDocument* aDocument,
                                  nsISupports* aContext,
                                  nsIURI* aURI,
                                  const nsAString &aType)
 {
   // Check that the containing page is allowed to load this URI.
   nsresult rv = nsContentUtils::GetSecurityManager()->
     CheckLoadURIWithPrincipal(aDocument->NodePrincipal(), aURI,
                               nsIScriptSecurityManager::ALLOW_CHROME);
   NS_ENSURE_SUCCESS(rv, rv);
   // After the security manager, the content-policy stuff gets a veto
   rv = CheckContentPolicy(aDocument, aContext, aURI, aType);
   if (NS_FAILED(rv)) {
     return rv;
   }
   return NS_OK;
 }
 nsresult
 nsScriptLoader::StartLoad(nsScriptLoadRequest *aRequest, const nsAString &aType,
                           bool aScriptFromHead)
 {
   nsISupports *context = aRequest->mElement.get()
                          ? static_cast<nsISupports *>(aRequest->mElement.get())
                          : static_cast<nsISupports *>(mDocument);
   nsresult rv = ShouldLoadScript(mDocument, context, aRequest->mURI, aType);
   if (NS_FAILED(rv)) {
     return rv;
   }
   nsCOMPtr<nsILoadGroup> loadGroup = mDocument->GetDocumentLoadGroup();
   nsCOMPtr<nsPIDOMWindow> window(do_QueryInterface(mDocument->GetWindow()));
   if (!window) {
     return NS_ERROR_NULL_POINTER;
   }
   nsIDocShell *docshell = window->GetDocShell();
   nsCOMPtr<nsIInterfaceRequestor> prompter(do_QueryInterface(docshell));
   // If this document is sandboxed without 'allow-scripts', abort.
   if (mDocument->GetSandboxFlags() & SANDBOXED_SCRIPTS) {
     return NS_OK;
   }
   // check for a Content Security Policy to pass down to the channel
   // that will be created to load the script
   nsCOMPtr<nsIChannelPolicy> channelPolicy;
   nsCOMPtr<nsIContentSecurityPolicy> csp;
   rv = mDocument->NodePrincipal()->GetCsp(getter_AddRefs(csp));
   NS_ENSURE_SUCCESS(rv, rv);
   if (csp) {
     channelPolicy = do_CreateInstance("@mozilla.org/nschannelpolicy;1");
     channelPolicy->SetContentSecurityPolicy(csp);
     channelPolicy->SetLoadType(nsIContentPolicy::TYPE_SCRIPT);
   }
   nsCOMPtr<nsIChannel> channel;
   rv = NS_NewChannel(getter_AddRefs(channel),
                      aRequest->mURI, nullptr, loadGroup, prompter,
                      nsIRequest::LOAD_NORMAL | nsIChannel::LOAD_CLASSIFY_URI,
                      channelPolicy);
   NS_ENSURE_SUCCESS(rv, rv);
   nsIScriptElement *script = aRequest->mElement;
   if (aScriptFromHead &&
       !(script && (script->GetScriptAsync() || script->GetScriptDeferred()))) {
     nsCOMPtr<nsIHttpChannelInternal>
       internalHttpChannel(do_QueryInterface(channel));
     if (internalHttpChannel)
       internalHttpChannel->SetLoadAsBlocking(true);
   }
   nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(channel));
   if (httpChannel) {
     // HTTP content negotation has little value in this context.
     httpChannel->SetRequestHeader(NS_LITERAL_CSTRING("Accept"),
                                   NS_LITERAL_CSTRING("*/*"),
                                   false);
     httpChannel->SetReferrer(mDocument->GetDocumentURI());
   }
   nsCOMPtr<nsILoadContext> loadContext(do_QueryInterface(docshell));
   mozilla::net::SeerLearn(aRequest->mURI, mDocument->GetDocumentURI(),
       nsINetworkSeer::LEARN_LOAD_SUBRESOURCE, loadContext);
   // Set the initiator type
   nsCOMPtr<nsITimedChannel> timedChannel(do_QueryInterface(httpChannel));
   if (timedChannel) {
     timedChannel->SetInitiatorType(NS_LITERAL_STRING("script"));
   }
   nsCOMPtr<nsIStreamLoader> loader;
   rv = NS_NewStreamLoader(getter_AddRefs(loader), this);
   NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIStreamListener> listener = loader.get();
   if (aRequest->mCORSMode != CORS_NONE) {
     bool withCredentials = (aRequest->mCORSMode == CORS_USE_CREDENTIALS);
     nsRefPtr<nsCORSListenerProxy> corsListener =
       new nsCORSListenerProxy(listener, mDocument->NodePrincipal(),
                               withCredentials);
     rv = corsListener->Init(channel);
     NS_ENSURE_SUCCESS(rv, rv);
     listener = corsListener;
   }
   rv = channel->AsyncOpen(listener, aRequest);
   NS_ENSURE_SUCCESS(rv, rv);
   return NS_OK;
 }
 bool
 nsScriptLoader::PreloadURIComparator::Equals(const PreloadInfo &aPi,
                                              nsIURI * const &aURI) const
 {
   bool same;
   return NS_SUCCEEDED(aPi.mRequest->mURI->Equals(aURI, &same)) &&
          same;
 }
 class nsScriptRequestProcessor : public nsRunnable
 {
 private:
   nsRefPtr<nsScriptLoader> mLoader;
   nsRefPtr<nsScriptLoadRequest> mRequest;
 public:
   nsScriptRequestProcessor(nsScriptLoader* aLoader,
                            nsScriptLoadRequest* aRequest)
     : mLoader(aLoader)
     , mRequest(aRequest)
   {}
   NS_IMETHODIMP Run()
   {
     return mLoader->ProcessRequest(mRequest);
   }
 };
 static inline bool
 ParseTypeAttribute(const nsAString& aType, JSVersion* aVersion)
 {
   MOZ_ASSERT(!aType.IsEmpty());
   MOZ_ASSERT(aVersion);
   MOZ_ASSERT(*aVersion == JSVERSION_DEFAULT);
   nsContentTypeParser parser(aType);
   nsAutoString mimeType;
   nsresult rv = parser.GetType(mimeType);
   NS_ENSURE_SUCCESS(rv, false);
   if (!nsContentUtils::IsJavascriptMIMEType(mimeType)) {
     return false;
   }
   // Get the version string, and ensure the language supports it.
   nsAutoString versionName;
   rv = parser.GetParameter("version", versionName);
   if (NS_SUCCEEDED(rv)) {
     *aVersion = nsContentUtils::ParseJavascriptVersion(versionName);
   } else if (rv != NS_ERROR_INVALID_ARG) {
     return false;
   }
   return true;
 }
 bool
 CSPAllowsInlineScript(nsIScriptElement *aElement, nsIDocument *aDocument)
 {
   nsCOMPtr<nsIContentSecurityPolicy> csp;
   nsresult rv = aDocument->NodePrincipal()->GetCsp(getter_AddRefs(csp));
   NS_ENSURE_SUCCESS(rv, false);
   if (!csp) {
     // no CSP --> allow
     return true;
   }
   // An inline script can be allowed because all inline scripts are allowed,
   // or else because it is whitelisted by a nonce-source or hash-source. This
   // is a logical OR between whitelisting methods, so the allowInlineScript
   // outparam can be reused for each check as long as we stop checking as soon
   // as it is set to true. This also optimizes performance by avoiding the
   // overhead of unnecessary checks.
   bool allowInlineScript = true;
   nsAutoTArray<unsigned short, 3> violations;
   bool reportInlineViolation = false;
   rv = csp->GetAllowsInlineScript(&reportInlineViolation, &allowInlineScript);
   NS_ENSURE_SUCCESS(rv, false);
   if (reportInlineViolation) {
     violations.AppendElement(static_cast<unsigned short>(
           nsIContentSecurityPolicy::VIOLATION_TYPE_INLINE_SCRIPT));
   }
   nsAutoString nonce;
   if (!allowInlineScript) {
     nsCOMPtr<nsIContent> scriptContent = do_QueryInterface(aElement);
     bool foundNonce = scriptContent->GetAttr(kNameSpaceID_None,
                                              nsGkAtoms::nonce, nonce);
     if (foundNonce) {
       bool reportNonceViolation;
       rv = csp->GetAllowsNonce(nonce, nsIContentPolicy::TYPE_SCRIPT,
                                &reportNonceViolation, &allowInlineScript);
       NS_ENSURE_SUCCESS(rv, false);
       if (reportNonceViolation) {
         violations.AppendElement(static_cast<unsigned short>(
               nsIContentSecurityPolicy::VIOLATION_TYPE_NONCE_SCRIPT));
       }
     }
   }
   if (!allowInlineScript) {
     bool reportHashViolation;
     nsAutoString scriptText;
     aElement->GetScriptText(scriptText);
     rv = csp->GetAllowsHash(scriptText, nsIContentPolicy::TYPE_SCRIPT,
                             &reportHashViolation, &allowInlineScript);
     NS_ENSURE_SUCCESS(rv, false);
     if (reportHashViolation) {
       violations.AppendElement(static_cast<unsigned short>(
             nsIContentSecurityPolicy::VIOLATION_TYPE_HASH_SCRIPT));
     }
   }
   // What violation(s) should be reported?
   //
   // 1. If the script tag has a nonce attribute, and the nonce does not match
   // the policy, report VIOLATION_TYPE_NONCE_SCRIPT.
   // 2. If the policy has at least one hash-source, and the hashed contents of
   // the script tag did not match any of them, report VIOLATION_TYPE_HASH_SCRIPT
   // 3. Otherwise, report VIOLATION_TYPE_INLINE_SCRIPT if appropriate.
   //
   // 1 and 2 may occur together, 3 should only occur by itself. Naturally,
   // every VIOLATION_TYPE_NONCE_SCRIPT and VIOLATION_TYPE_HASH_SCRIPT are also
   // VIOLATION_TYPE_INLINE_SCRIPT, but reporting the
   // VIOLATION_TYPE_INLINE_SCRIPT is redundant and does not help the developer.
   if (!violations.IsEmpty()) {
     MOZ_ASSERT(violations[0] == nsIContentSecurityPolicy::VIOLATION_TYPE_INLINE_SCRIPT,
                "How did we get any violations without an initial inline script violation?");
     // gather information to log with violation report
     nsIURI* uri = aDocument->GetDocumentURI();
     nsAutoCString asciiSpec;
     uri->GetAsciiSpec(asciiSpec);
     nsAutoString scriptText;
     aElement->GetScriptText(scriptText);
     nsAutoString scriptSample(scriptText);
     // cap the length of the script sample at 40 chars
     if (scriptSample.Length() > 40) {
       scriptSample.Truncate(40);
       scriptSample.AppendLiteral("...");
     }
     for (uint32_t i = 0; i < violations.Length(); i++) {
       // Skip reporting the redundant inline script violation if there are
       // other (nonce and/or hash violations) as well.
       if (i > 0 || violations.Length() == 1) {
         csp->LogViolationDetails(violations[i], NS_ConvertUTF8toUTF16(asciiSpec),
                                  scriptSample, aElement->GetScriptLineNumber(),
                                  nonce, scriptText);
       }
     }
   }
   if (!allowInlineScript) {
     NS_ASSERTION(!violations.IsEmpty(),
         "CSP blocked inline script but is not reporting a violation");
    return false;
   }
   return true;
 }
 bool
 nsScriptLoader::ProcessScriptElement(nsIScriptElement *aElement)
 {
   // We need a document to evaluate scripts.
   NS_ENSURE_TRUE(mDocument, false);
   // Check to see if scripts has been turned off.
   if (!mEnabled || !mDocument->IsScriptEnabled()) {
     return false;
   }
   NS_ASSERTION(!aElement->IsMalformed(), "Executing malformed script");
   nsCOMPtr<nsIContent> scriptContent = do_QueryInterface(aElement);
   // Step 12. Check that the script is not an eventhandler
   if (IsScriptEventHandler(scriptContent)) {
     return false;
   }
   JSVersion version = JSVERSION_DEFAULT;
   // Check the type attribute to determine language and version.
   // If type exists, it trumps the deprecated 'language='
   nsAutoString type;
   aElement->GetScriptType(type);
   if (!type.IsEmpty()) {
     NS_ENSURE_TRUE(ParseTypeAttribute(type, &version), false);
   } else {
     // no 'type=' element
     // "language" is a deprecated attribute of HTML, so we check it only for
     // HTML script elements.
     if (scriptContent->IsHTML()) {
       nsAutoString language;
       scriptContent->GetAttr(kNameSpaceID_None, nsGkAtoms::language, language);
       if (!language.IsEmpty()) {
         if (!nsContentUtils::IsJavaScriptLanguage(language)) {
           return false;
         }
       }
     }
   }
   // Step 14. in the HTML5 spec
   nsresult rv = NS_OK;
   nsRefPtr<nsScriptLoadRequest> request;
   if (aElement->GetScriptExternal()) {
     // external script
     nsCOMPtr<nsIURI> scriptURI = aElement->GetScriptURI();
     if (!scriptURI) {
       // Asynchronously report the failure to create a URI object
       NS_DispatchToCurrentThread(
         NS_NewRunnableMethod(aElement,
                              &nsIScriptElement::FireErrorEvent));
       return false;
     }
     CORSMode ourCORSMode = aElement->GetCORSMode();
     nsTArray<PreloadInfo>::index_type i =
       mPreloads.IndexOf(scriptURI.get(), 0, PreloadURIComparator());
     if (i != nsTArray<PreloadInfo>::NoIndex) {
       // preloaded
       // note that a script-inserted script can steal a preload!
       request = mPreloads[i].mRequest;
       request->mElement = aElement;
       nsString preloadCharset(mPreloads[i].mCharset);
       mPreloads.RemoveElementAt(i);
       // Double-check that the charset the preload used is the same as
       // the charset we have now.
       nsAutoString elementCharset;
       aElement->GetScriptCharset(elementCharset);
       if (elementCharset.Equals(preloadCharset) &&
           ourCORSMode == request->mCORSMode) {
         rv = CheckContentPolicy(mDocument, aElement, request->mURI, type);
         NS_ENSURE_SUCCESS(rv, false);
       } else {
         // Drop the preload
         request = nullptr;
       }
     }
     if (!request) {
       // no usable preload
       request = new nsScriptLoadRequest(aElement, version, ourCORSMode);
       request->mURI = scriptURI;
       request->mIsInline = false;
       request->mLoading = true;
       // set aScriptFromHead to false so we don't treat non preloaded scripts as
       // blockers for full page load. See bug 792438.
       rv = StartLoad(request, type, false);
       if (NS_FAILED(rv)) {
         // Asynchronously report the load failure
         NS_DispatchToCurrentThread(
           NS_NewRunnableMethod(aElement,
                                &nsIScriptElement::FireErrorEvent));
         return false;
       }
     }
     request->mJSVersion = version;
     if (aElement->GetScriptAsync()) {
       mAsyncRequests.AppendElement(request);
       if (!request->mLoading) {
         // The script is available already. Run it ASAP when the event
         // loop gets a chance to spin.
         ProcessPendingRequestsAsync();
       }
       return false;
     }
     if (!aElement->GetParserCreated()) {
       // Violate the HTML5 spec in order to make LABjs and the "order" plug-in
       // for RequireJS work with their Gecko-sniffed code path. See
       // http://lists.w3.org/Archives/Public/public-html/2010Oct/0088.html
       mNonAsyncExternalScriptInsertedRequests.AppendElement(request);
       if (!request->mLoading) {
         // The script is available already. Run it ASAP when the event
         // loop gets a chance to spin.
         ProcessPendingRequestsAsync();
       }
       return false;
     }
     // we now have a parser-inserted request that may or may not be still
     // loading
     if (aElement->GetScriptDeferred()) {
       // We don't want to run this yet.
       // If we come here, the script is a parser-created script and it has
       // the defer attribute but not the async attribute. Since a
       // a parser-inserted script is being run, we came here by the parser
       // running the script, which means the parser is still alive and the
       // parse is ongoing.
       NS_ASSERTION(mDocument->GetCurrentContentSink() ||
                    aElement->GetParserCreated() == FROM_PARSER_XSLT,
           "Non-XSLT Defer script on a document without an active parser; bug 592366.");
       AddDeferRequest(request);
       return false;
     }
     if (aElement->GetParserCreated() == FROM_PARSER_XSLT) {
       // Need to maintain order for XSLT-inserted scripts
       NS_ASSERTION(!mParserBlockingRequest,
           "Parser-blocking scripts and XSLT scripts in the same doc!");
       mXSLTRequests.AppendElement(request);
       if (!request->mLoading) {
         // The script is available already. Run it ASAP when the event
         // loop gets a chance to spin.
         ProcessPendingRequestsAsync();
       }
       return true;
     }
     if (!request->mLoading && ReadyToExecuteScripts()) {
       // The request has already been loaded and there are no pending style
       // sheets. If the script comes from the network stream, cheat for
       // performance reasons and avoid a trip through the event loop.
       if (aElement->GetParserCreated() == FROM_PARSER_NETWORK) {
         return ProcessRequest(request) == NS_ERROR_HTMLPARSER_BLOCK;
       }
       // Otherwise, we've got a document.written script, make a trip through
       // the event loop to hide the preload effects from the scripts on the
       // Web page.
       NS_ASSERTION(!mParserBlockingRequest,
           "There can be only one parser-blocking script at a time");
       NS_ASSERTION(mXSLTRequests.IsEmpty(),
           "Parser-blocking scripts and XSLT scripts in the same doc!");
       mParserBlockingRequest = request;
       ProcessPendingRequestsAsync();
       return true;
     }
     // The script hasn't loaded yet or there's a style sheet blocking it.
     // The script will be run when it loads or the style sheet loads.
     NS_ASSERTION(!mParserBlockingRequest,
         "There can be only one parser-blocking script at a time");
     NS_ASSERTION(mXSLTRequests.IsEmpty(),
         "Parser-blocking scripts and XSLT scripts in the same doc!");
     mParserBlockingRequest = request;
     return true;
   }
   // inline script
   // Is this document sandboxed without 'allow-scripts'?
   if (mDocument->GetSandboxFlags() & SANDBOXED_SCRIPTS) {
     return false;
   }
   // Does CSP allow this inline script to run?
   if (!CSPAllowsInlineScript(aElement, mDocument)) {
     return false;
   }
   // Inline scripts ignore ther CORS mode and are always CORS_NONE
   request = new nsScriptLoadRequest(aElement, version, CORS_NONE);
   request->mJSVersion = version;
   request->mLoading = false;
   request->mIsInline = true;
   request->mURI = mDocument->GetDocumentURI();
   request->mLineNo = aElement->GetScriptLineNumber();
   if (aElement->GetParserCreated() == FROM_PARSER_XSLT &&
       (!ReadyToExecuteScripts() || !mXSLTRequests.IsEmpty())) {
     // Need to maintain order for XSLT-inserted scripts
     NS_ASSERTION(!mParserBlockingRequest,
         "Parser-blocking scripts and XSLT scripts in the same doc!");
     mXSLTRequests.AppendElement(request);
     return true;
   }
   if (aElement->GetParserCreated() == NOT_FROM_PARSER) {
     NS_ASSERTION(!nsContentUtils::IsSafeToRunScript(),
         "A script-inserted script is inserted without an update batch?");
     nsContentUtils::AddScriptRunner(new nsScriptRequestProcessor(this,
                                                                  request));
     return false;
   }
   if (aElement->GetParserCreated() == FROM_PARSER_NETWORK &&
       !ReadyToExecuteScripts()) {
     NS_ASSERTION(!mParserBlockingRequest,
         "There can be only one parser-blocking script at a time");
     mParserBlockingRequest = request;
     NS_ASSERTION(mXSLTRequests.IsEmpty(),
         "Parser-blocking scripts and XSLT scripts in the same doc!");
     return true;
   }
   // We now have a document.written inline script or we have an inline script
   // from the network but there is no style sheet that is blocking scripts.
   // Don't check for style sheets blocking scripts in the document.write
   // case to avoid style sheet network activity affecting when
   // document.write returns. It's not really necessary to do this if
   // there's no document.write currently on the call stack. However,
   // this way matches IE more closely than checking if document.write
   // is on the call stack.
   NS_ASSERTION(nsContentUtils::IsSafeToRunScript(),
       "Not safe to run a parser-inserted script?");
   return ProcessRequest(request) == NS_ERROR_HTMLPARSER_BLOCK;
 }
 namespace {
 class NotifyOffThreadScriptLoadCompletedRunnable : public nsRunnable
 {
   nsRefPtr<nsScriptLoadRequest> mRequest;
   nsRefPtr<nsScriptLoader> mLoader;
   void *mToken;
 public:
   NotifyOffThreadScriptLoadCompletedRunnable(nsScriptLoadRequest* aRequest,
                                              nsScriptLoader* aLoader)
     : mRequest(aRequest), mLoader(aLoader), mToken(nullptr)
   {}
   void SetToken(void* aToken) {
     MOZ_ASSERT(aToken && !mToken);
     mToken = aToken;
   }
   NS_DECL_NSIRUNNABLE
 };
 } /* anonymous namespace */
 nsresult
 nsScriptLoader::ProcessOffThreadRequest(nsScriptLoadRequest* aRequest, void **aOffThreadToken)
 {
   nsresult rv = ProcessRequest(aRequest, aOffThreadToken);
   mDocument->UnblockOnload(false);
   return rv;
 }
 NS_IMETHODIMP
 NotifyOffThreadScriptLoadCompletedRunnable::Run()
 {
   MOZ_ASSERT(NS_IsMainThread());
   nsresult rv = mLoader->ProcessOffThreadRequest(mRequest, &mToken);
   if (mToken) {
     // The result of the off thread parse was not actually needed to process
     // the request (disappearing window, some other error, ...). Finish the
     // request to avoid leaks in the JS engine.
     nsCOMPtr<nsIJSRuntimeService> svc = do_GetService("@mozilla.org/js/xpc/RuntimeService;1");
     NS_ENSURE_TRUE(svc, NS_ERROR_FAILURE);
     JSRuntime *rt;
     svc->GetRuntime(&rt);
     NS_ENSURE_TRUE(rt, NS_ERROR_FAILURE);
     JS::FinishOffThreadScript(nullptr, rt, mToken);
   }
   return rv;
 }
 static void
 OffThreadScriptLoaderCallback(void *aToken, void *aCallbackData)
 {
   nsRefPtr<NotifyOffThreadScriptLoadCompletedRunnable> aRunnable =
     dont_AddRef(static_cast<NotifyOffThreadScriptLoadCompletedRunnable*>(aCallbackData));
   aRunnable->SetToken(aToken);
   NS_DispatchToMainThread(aRunnable);
 }
 nsresult
 nsScriptLoader::AttemptAsyncScriptParse(nsScriptLoadRequest* aRequest)
 {
   if (!aRequest->mElement->GetScriptAsync() || aRequest->mIsInline) {
     return NS_ERROR_FAILURE;
   }
   nsCOMPtr<nsIScriptGlobalObject> globalObject = GetScriptGlobalObject();
   if (!globalObject) {
     return NS_ERROR_FAILURE;
   }
   nsCOMPtr<nsIScriptContext> context = globalObject->GetScriptContext();
   if (!context) {
     return NS_ERROR_FAILURE;
   }
   AutoPushJSContext cx(context->GetNativeContext());
   JS::Rooted<JSObject*> global(cx, globalObject->GetGlobalJSObject());
   JS::CompileOptions options(cx);
   FillCompileOptionsForRequest(aRequest, global, &options);
   if (!JS::CanCompileOffThread(cx, options, aRequest->mScriptTextLength)) {
     return NS_ERROR_FAILURE;
   }
   nsRefPtr<NotifyOffThreadScriptLoadCompletedRunnable> runnable =
     new NotifyOffThreadScriptLoadCompletedRunnable(aRequest, this);
   if (!JS::CompileOffThread(cx, options,
                             aRequest->mScriptTextBuf, aRequest->mScriptTextLength,
                             OffThreadScriptLoaderCallback,
                             static_cast<void*>(runnable))) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
   mDocument->BlockOnload();
   unused << runnable.forget();
   return NS_OK;
 }
 nsresult
 nsScriptLoader::ProcessRequest(nsScriptLoadRequest* aRequest, void **aOffThreadToken)
 {
   NS_ASSERTION(nsContentUtils::IsSafeToRunScript(),
                "Processing requests when running scripts is unsafe.");
   if (!aOffThreadToken) {
     nsresult rv = AttemptAsyncScriptParse(aRequest);
     if (rv != NS_ERROR_FAILURE)
       return rv;
   }
   NS_ENSURE_ARG(aRequest);
   nsAutoString textData;
   const jschar* scriptBuf = nullptr;
   size_t scriptLength = 0;
   JS::SourceBufferHolder::Ownership giveScriptOwnership =
     JS::SourceBufferHolder::NoOwnership;
   nsCOMPtr<nsIDocument> doc;
   nsCOMPtr<nsINode> scriptElem = do_QueryInterface(aRequest->mElement);
   // If there's no script text, we try to get it from the element
   if (aRequest->mIsInline) {
     // XXX This is inefficient - GetText makes multiple
     // copies.
     aRequest->mElement->GetScriptText(textData);
     scriptBuf = textData.get();
     scriptLength = textData.Length();
     giveScriptOwnership = JS::SourceBufferHolder::NoOwnership;
   }
   else {
     scriptBuf = aRequest->mScriptTextBuf;
     scriptLength = aRequest->mScriptTextLength;
     giveScriptOwnership = JS::SourceBufferHolder::GiveOwnership;
     aRequest->mScriptTextBuf = nullptr;
     aRequest->mScriptTextLength = 0;
     doc = scriptElem->OwnerDoc();
   }
   JS::SourceBufferHolder srcBuf(scriptBuf, scriptLength, giveScriptOwnership);
   nsCOMPtr<nsIScriptElement> oldParserInsertedScript;
   uint32_t parserCreated = aRequest->mElement->GetParserCreated();
   if (parserCreated) {
     oldParserInsertedScript = mCurrentParserInsertedScript;
     mCurrentParserInsertedScript = aRequest->mElement;
   }
   FireScriptAvailable(NS_OK, aRequest);
   // The window may have gone away by this point, in which case there's no point
   // in trying to run the script.
   nsPIDOMWindow *pwin = mDocument->GetInnerWindow();
   bool runScript = !!pwin;
   if (runScript) {
     nsContentUtils::DispatchTrustedEvent(scriptElem->OwnerDoc(),
                                          scriptElem,
                                          NS_LITERAL_STRING("beforescriptexecute"),
                                          true, true, &runScript);
   }
   // Inner window could have gone away after firing beforescriptexecute
   pwin = mDocument->GetInnerWindow();
   if (!pwin) {
     runScript = false;
   }
   nsresult rv = NS_OK;
   if (runScript) {
     if (doc) {
       doc->BeginEvaluatingExternalScript();
     }
     aRequest->mElement->BeginEvaluating();
     rv = EvaluateScript(aRequest, srcBuf, aOffThreadToken);
     aRequest->mElement->EndEvaluating();
     if (doc) {
       doc->EndEvaluatingExternalScript();
     }
     nsContentUtils::DispatchTrustedEvent(scriptElem->OwnerDoc(),
                                          scriptElem,
                                          NS_LITERAL_STRING("afterscriptexecute"),
                                          true, false);
   }
   FireScriptEvaluated(rv, aRequest);
   if (parserCreated) {
     mCurrentParserInsertedScript = oldParserInsertedScript;
   }
   return rv;
 }
 void
 nsScriptLoader::FireScriptAvailable(nsresult aResult,
                                     nsScriptLoadRequest* aRequest)
 {
   for (int32_t i = 0; i < mObservers.Count(); i++) {
     nsCOMPtr<nsIScriptLoaderObserver> obs = mObservers[i];
     obs->ScriptAvailable(aResult, aRequest->mElement,
                          aRequest->mIsInline, aRequest->mURI,
                          aRequest->mLineNo);
   }
   aRequest->FireScriptAvailable(aResult);
 }
 void
 nsScriptLoader::FireScriptEvaluated(nsresult aResult,
                                     nsScriptLoadRequest* aRequest)
 {
   for (int32_t i = 0; i < mObservers.Count(); i++) {
     nsCOMPtr<nsIScriptLoaderObserver> obs = mObservers[i];
     obs->ScriptEvaluated(aResult, aRequest->mElement,
                          aRequest->mIsInline);
   }
   aRequest->FireScriptEvaluated(aResult);
 }
 already_AddRefed<nsIScriptGlobalObject>
 nsScriptLoader::GetScriptGlobalObject()
 {
   nsPIDOMWindow *pwin = mDocument->GetInnerWindow();
   if (!pwin) {
     return nullptr;
   }
   nsCOMPtr<nsIScriptGlobalObject> globalObject = do_QueryInterface(pwin);
   NS_ASSERTION(globalObject, "windows must be global objects");
   // and make sure we are setup for this type of script.
   nsresult rv = globalObject->EnsureScriptEnvironment();
   if (NS_FAILED(rv)) {
     return nullptr;
   }
   return globalObject.forget();
 }
 void
 nsScriptLoader::FillCompileOptionsForRequest(nsScriptLoadRequest *aRequest,
                                              JS::Handle<JSObject *> aScopeChain,
                                              JS::CompileOptions *aOptions)
 {
   // It's very important to use aRequest->mURI, not the final URI of the channel
   // aRequest ended up getting script data from, as the script filename.
   nsContentUtils::GetWrapperSafeScriptFilename(mDocument, aRequest->mURI, aRequest->mURL);
   aOptions->setIntroductionType("scriptElement");
   aOptions->setFileAndLine(aRequest->mURL.get(), aRequest->mLineNo);
   aOptions->setVersion(JSVersion(aRequest->mJSVersion));
   aOptions->setCompileAndGo(JS_IsGlobalObject(aScopeChain));
   if (aRequest->mHasSourceMapURL) {
     aOptions->setSourceMapURL(aRequest->mSourceMapURL.get());
   }
   if (aRequest->mOriginPrincipal) {
     aOptions->setOriginPrincipals(nsJSPrincipals::get(aRequest->mOriginPrincipal));
   }
   AutoJSContext cx;
   JS::Rooted<JS::Value> elementVal(cx);
   MOZ_ASSERT(aRequest->mElement);
   // XXXbz this is super-fragile, because the code that _uses_ the
   // JS::CompileOptions is nowhere near us, but we have to coordinate
   // compartments with it... and in particular, it will compile in the
   // compartment of aScopeChain, so we want to wrap into that compartment as
   // well.
   JSAutoCompartment ac(cx, aScopeChain);
   if (NS_SUCCEEDED(nsContentUtils::WrapNative(cx, aRequest->mElement,
                                               &elementVal,
                                               /* aAllowWrapping = */ true))) {
     MOZ_ASSERT(elementVal.isObject());
     aOptions->setElement(&elementVal.toObject());
   }
 }
 nsresult
 nsScriptLoader::EvaluateScript(nsScriptLoadRequest* aRequest,
                                JS::SourceBufferHolder& aSrcBuf,
                                void** aOffThreadToken)
 {
   // We need a document to evaluate scripts.
   if (!mDocument) {
     return NS_ERROR_FAILURE;
   }
   nsCOMPtr<nsIContent> scriptContent(do_QueryInterface(aRequest->mElement));
   nsIDocument* ownerDoc = scriptContent->OwnerDoc();
   if (ownerDoc != mDocument) {
     // Willful violation of HTML5 as of 2010-12-01
     return NS_ERROR_FAILURE;
   }
   // Get the script-type to be used by this element.
   NS_ASSERTION(scriptContent, "no content - what is default script-type?");
   nsCOMPtr<nsIScriptGlobalObject> globalObject = GetScriptGlobalObject();
   if (!globalObject) {
     return NS_ERROR_FAILURE;
   }
   // Make sure context is a strong reference since we access it after
   // we've executed a script, which may cause all other references to
   // the context to go away.
   nsCOMPtr<nsIScriptContext> context = globalObject->GetScriptContext();
   if (!context) {
     return NS_ERROR_FAILURE;
   }
   JSVersion version = JSVersion(aRequest->mJSVersion);
   if (version == JSVERSION_UNKNOWN) {
     return NS_OK;
   }
   // New script entry point required, due to the "Create a script" sub-step of
   // http://www.whatwg.org/specs/web-apps/current-work/#execute-the-script-block
   AutoEntryScript entryScript(globalObject, true, context->GetNativeContext());
   JS::Rooted<JSObject*> global(entryScript.cx(),
                                globalObject->GetGlobalJSObject());
   bool oldProcessingScriptTag = context->GetProcessingScriptTag();
   context->SetProcessingScriptTag(true);
   // Update our current script.
   nsCOMPtr<nsIScriptElement> oldCurrent = mCurrentScript;
   mCurrentScript = aRequest->mElement;
   JS::CompileOptions options(entryScript.cx());
   FillCompileOptionsForRequest(aRequest, global, &options);
   nsresult rv = nsJSUtils::EvaluateString(entryScript.cx(), aSrcBuf, global, options,
                                           aOffThreadToken);
   // Put the old script back in case it wants to do anything else.
   mCurrentScript = oldCurrent;
   context->SetProcessingScriptTag(oldProcessingScriptTag);
   return rv;
 }
 void
 nsScriptLoader::ProcessPendingRequestsAsync()
 {
   if (mParserBlockingRequest || !mPendingChildLoaders.IsEmpty()) {
     nsCOMPtr<nsIRunnable> ev = NS_NewRunnableMethod(this,
       &nsScriptLoader::ProcessPendingRequests);
     NS_DispatchToCurrentThread(ev);
   }
 }
 void
 nsScriptLoader::ProcessPendingRequests()
 {
   nsRefPtr<nsScriptLoadRequest> request;
   if (mParserBlockingRequest &&
       !mParserBlockingRequest->mLoading &&
       ReadyToExecuteScripts()) {
     request.swap(mParserBlockingRequest);
     UnblockParser(request);
     ProcessRequest(request);
     ContinueParserAsync(request);
   }
   while (ReadyToExecuteScripts() &&
          !mXSLTRequests.IsEmpty() &&
          !mXSLTRequests[0]->mLoading) {
     request.swap(mXSLTRequests[0]);
     mXSLTRequests.RemoveElementAt(0);
     ProcessRequest(request);
   }
   uint32_t i = 0;
   while (mEnabled && i < mAsyncRequests.Length()) {
     if (!mAsyncRequests[i]->mLoading) {
       request.swap(mAsyncRequests[i]);
       mAsyncRequests.RemoveElementAt(i);
       ProcessRequest(request);
       continue;
     }
     ++i;
   }
   while (mEnabled && !mNonAsyncExternalScriptInsertedRequests.IsEmpty() &&
          !mNonAsyncExternalScriptInsertedRequests[0]->mLoading) {
     // Violate the HTML5 spec and execute these in the insertion order in
     // order to make LABjs and the "order" plug-in for RequireJS work with
     // their Gecko-sniffed code path. See
     // http://lists.w3.org/Archives/Public/public-html/2010Oct/0088.html
     request.swap(mNonAsyncExternalScriptInsertedRequests[0]);
     mNonAsyncExternalScriptInsertedRequests.RemoveElementAt(0);
     ProcessRequest(request);
   }
   if (mDocumentParsingDone && mXSLTRequests.IsEmpty()) {
     while (!mDeferRequests.IsEmpty() && !mDeferRequests[0]->mLoading) {
       request.swap(mDeferRequests[0]);
       mDeferRequests.RemoveElementAt(0);
       ProcessRequest(request);
     }
   }
   while (!mPendingChildLoaders.IsEmpty() && ReadyToExecuteScripts()) {
     nsRefPtr<nsScriptLoader> child = mPendingChildLoaders[0];
     mPendingChildLoaders.RemoveElementAt(0);
     child->RemoveExecuteBlocker();
   }
   if (mDocumentParsingDone && mDocument &&
       !mParserBlockingRequest && mAsyncRequests.IsEmpty() &&
       mNonAsyncExternalScriptInsertedRequests.IsEmpty() &&
       mXSLTRequests.IsEmpty() && mDeferRequests.IsEmpty()) {
     if (MaybeRemovedDeferRequests()) {
       return ProcessPendingRequests();
     }
     // No more pending scripts; time to unblock onload.
     // OK to unblock onload synchronously here, since callers must be
     // prepared for the world changing anyway.
     mDocumentParsingDone = false;
     mDocument->UnblockOnload(true);
   }
 }
 bool
 nsScriptLoader::ReadyToExecuteScripts()
 {
   // Make sure the SelfReadyToExecuteScripts check is first, so that
   // we don't block twice on an ancestor.
   if (!SelfReadyToExecuteScripts()) {
     return false;
   }
   for (nsIDocument* doc = mDocument; doc; doc = doc->GetParentDocument()) {
     nsScriptLoader* ancestor = doc->ScriptLoader();
     if (!ancestor->SelfReadyToExecuteScripts() &&
         ancestor->AddPendingChildLoader(this)) {
       AddExecuteBlocker();
       return false;
     }
   }
   return true;
 }
 // This function was copied from nsParser.cpp. It was simplified a bit.
 static bool
 DetectByteOrderMark(const unsigned char* aBytes, int32_t aLen, nsCString& oCharset)
 {
   if (aLen < 2)
     return false;
   switch(aBytes[0]) {
   case 0xEF:
     if (aLen >= 3 && 0xBB == aBytes[1] && 0xBF == aBytes[2]) {
       // EF BB BF
       // Win2K UTF-8 BOM
       oCharset.Assign("UTF-8");
     }
     break;
   case 0xFE:
     if (0xFF == aBytes[1]) {
       // FE FF
       // UTF-16, big-endian
       oCharset.Assign("UTF-16BE");
     }
     break;
   case 0xFF:
     if (0xFE == aBytes[1]) {
       // FF FE
       // UTF-16, little-endian
       oCharset.Assign("UTF-16LE");
     }
     break;
   }
   return !oCharset.IsEmpty();
 }
 /* static */ nsresult
 nsScriptLoader::ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
                                uint32_t aLength, const nsAString& aHintCharset,
                                nsIDocument* aDocument,
                                jschar*& aBufOut, size_t& aLengthOut)
 {
   if (!aLength) {
     aBufOut = nullptr;
     aLengthOut = 0;
     return NS_OK;
   }
   // The encoding info precedence is as follows from high to low:
   // The BOM
   // HTTP Content-Type (if name recognized)
   // charset attribute (if name recognized)
   // The encoding of the document
   nsAutoCString charset;
   nsCOMPtr<nsIUnicodeDecoder> unicodeDecoder;
   if (DetectByteOrderMark(aData, aLength, charset)) {
     // charset is now "UTF-8" or "UTF-16". The UTF-16 decoder will re-sniff
     // the BOM for endianness. Both the UTF-16 and the UTF-8 decoder will
     // take care of swallowing the BOM.
     unicodeDecoder = EncodingUtils::DecoderForEncoding(charset);
   }
   if (!unicodeDecoder &&
       aChannel &&
       NS_SUCCEEDED(aChannel->GetContentCharset(charset)) &&
       EncodingUtils::FindEncodingForLabel(charset, charset)) {
     unicodeDecoder = EncodingUtils::DecoderForEncoding(charset);
   }
   if (!unicodeDecoder &&
       EncodingUtils::FindEncodingForLabel(aHintCharset, charset)) {
     unicodeDecoder = EncodingUtils::DecoderForEncoding(charset);
   }
   if (!unicodeDecoder && aDocument) {
     charset = aDocument->GetDocumentCharacterSet();
     unicodeDecoder = EncodingUtils::DecoderForEncoding(charset);
   }
   if (!unicodeDecoder) {
     // Curiously, there are various callers that don't pass aDocument. The
     // fallback in the old code was ISO-8859-1, which behaved like
     // windows-1252. Saying windows-1252 for clarity and for compliance
     // with the Encoding Standard.
     unicodeDecoder = EncodingUtils::DecoderForEncoding("windows-1252");
   }
   int32_t unicodeLength = 0;
   nsresult rv =
     unicodeDecoder->GetMaxLength(reinterpret_cast<const char*>(aData),
                                  aLength, &unicodeLength);
   NS_ENSURE_SUCCESS(rv, rv);
   aBufOut = static_cast<jschar*>(js_malloc(unicodeLength * sizeof(jschar)));
   if (!aBufOut) {
     aLengthOut = 0;
     return NS_ERROR_OUT_OF_MEMORY;
   }
   aLengthOut = unicodeLength;
   rv = unicodeDecoder->Convert(reinterpret_cast<const char*>(aData),
                                (int32_t *) &aLength, aBufOut,
                                &unicodeLength);
   MOZ_ASSERT(NS_SUCCEEDED(rv));
   aLengthOut = unicodeLength;
   if (NS_FAILED(rv)) {
     js_free(aBufOut);
     aBufOut = nullptr;
     aLengthOut = 0;
   }
   return rv;
 }
 NS_IMETHODIMP
 nsScriptLoader::OnStreamComplete(nsIStreamLoader* aLoader,
                                  nsISupports* aContext,
                                  nsresult aStatus,
                                  uint32_t aStringLen,
                                  const uint8_t* aString)
 {
   nsScriptLoadRequest* request = static_cast<nsScriptLoadRequest*>(aContext);
   NS_ASSERTION(request, "null request in stream complete handler");
   NS_ENSURE_TRUE(request, NS_ERROR_FAILURE);
   nsresult rv = PrepareLoadedRequest(request, aLoader, aStatus, aStringLen,
                                      aString);
   if (NS_FAILED(rv)) {
     if (mDeferRequests.RemoveElement(request) ||
         mAsyncRequests.RemoveElement(request) ||
         mNonAsyncExternalScriptInsertedRequests.RemoveElement(request) ||
         mXSLTRequests.RemoveElement(request)) {
       FireScriptAvailable(rv, request);
     } else if (mParserBlockingRequest == request) {
       mParserBlockingRequest = nullptr;
       UnblockParser(request);
       FireScriptAvailable(rv, request);
       ContinueParserAsync(request);
     } else {
       mPreloads.RemoveElement(request, PreloadRequestComparator());
     }
     rv = NS_OK;
   } else {
     NS_Free(const_cast<uint8_t *>(aString));
     rv = NS_SUCCESS_ADOPTED_DATA;
   }
   // Process our request and/or any pending ones
   ProcessPendingRequests();
   return rv;
 }
 void
 nsScriptLoader::UnblockParser(nsScriptLoadRequest* aParserBlockingRequest)
 {
   aParserBlockingRequest->mElement->UnblockParser();
 }
 void
 nsScriptLoader::ContinueParserAsync(nsScriptLoadRequest* aParserBlockingRequest)
 {
   aParserBlockingRequest->mElement->ContinueParserAsync();
 }
 nsresult
 nsScriptLoader::PrepareLoadedRequest(nsScriptLoadRequest* aRequest,
                                      nsIStreamLoader* aLoader,
                                      nsresult aStatus,
                                      uint32_t aStringLen,
                                      const uint8_t* aString)
 {
   if (NS_FAILED(aStatus)) {
     return aStatus;
   }
   // If we don't have a document, then we need to abort further
   // evaluation.
   if (!mDocument) {
     return NS_ERROR_NOT_AVAILABLE;
   }
   // If the load returned an error page, then we need to abort
   nsCOMPtr<nsIRequest> req;
   nsresult rv = aLoader->GetRequest(getter_AddRefs(req));
   NS_ASSERTION(req, "StreamLoader's request went away prematurely");
   NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(req);
   if (httpChannel) {
     bool requestSucceeded;
     rv = httpChannel->GetRequestSucceeded(&requestSucceeded);
     if (NS_SUCCEEDED(rv) && !requestSucceeded) {
       return NS_ERROR_NOT_AVAILABLE;
     }
     nsAutoCString sourceMapURL;
     httpChannel->GetResponseHeader(NS_LITERAL_CSTRING("X-SourceMap"), sourceMapURL);
     aRequest->mHasSourceMapURL = true;
     aRequest->mSourceMapURL = NS_ConvertUTF8toUTF16(sourceMapURL);
   }
   nsCOMPtr<nsIChannel> channel = do_QueryInterface(req);
   // If this load was subject to a CORS check; don't flag it with a
   // separate origin principal, so that it will treat our document's
   // principal as the origin principal
   if (aRequest->mCORSMode == CORS_NONE) {
     rv = nsContentUtils::GetSecurityManager()->
       GetChannelPrincipal(channel, getter_AddRefs(aRequest->mOriginPrincipal));
     NS_ENSURE_SUCCESS(rv, rv);
   }
   if (aStringLen) {
     // Check the charset attribute to determine script charset.
     nsAutoString hintCharset;
     if (!aRequest->IsPreload()) {
       aRequest->mElement->GetScriptCharset(hintCharset);
     } else {
       nsTArray<PreloadInfo>::index_type i =
         mPreloads.IndexOf(aRequest, 0, PreloadRequestComparator());
       NS_ASSERTION(i != mPreloads.NoIndex, "Incorrect preload bookkeeping");
       hintCharset = mPreloads[i].mCharset;
     }
     rv = ConvertToUTF16(channel, aString, aStringLen, hintCharset, mDocument,
                         aRequest->mScriptTextBuf, aRequest->mScriptTextLength);
     NS_ENSURE_SUCCESS(rv, rv);
   }
   // This assertion could fire errorously if we ran out of memory when
   // inserting the request in the array. However it's an unlikely case
   // so if you see this assertion it is likely something else that is
   // wrong, especially if you see it more than once.
   NS_ASSERTION(mDeferRequests.Contains(aRequest) ||
                mAsyncRequests.Contains(aRequest) ||
                mNonAsyncExternalScriptInsertedRequests.Contains(aRequest) ||
                mXSLTRequests.Contains(aRequest)  ||
                mPreloads.Contains(aRequest, PreloadRequestComparator()) ||
                mParserBlockingRequest,
                "aRequest should be pending!");
   // Mark this as loaded
   aRequest->mLoading = false;
   return NS_OK;
 }
 void
 nsScriptLoader::ParsingComplete(bool aTerminated)
 {
   if (mDeferEnabled) {
     // Have to check because we apparently get ParsingComplete
     // without BeginDeferringScripts in some cases
     mDocumentParsingDone = true;
   }
   mDeferEnabled = false;
   if (aTerminated) {
     mDeferRequests.Clear();
     mAsyncRequests.Clear();
     mNonAsyncExternalScriptInsertedRequests.Clear();
     mXSLTRequests.Clear();
     mParserBlockingRequest = nullptr;
   }
   // Have to call this even if aTerminated so we'll correctly unblock
   // onload and all.
   ProcessPendingRequests();
 }
 void
 nsScriptLoader::PreloadURI(nsIURI *aURI, const nsAString &aCharset,
                            const nsAString &aType,
                            const nsAString &aCrossOrigin,
                            bool aScriptFromHead)
 {
   // Check to see if scripts has been turned off.
   if (!mEnabled || !mDocument->IsScriptEnabled()) {
     return;
   }
   nsRefPtr<nsScriptLoadRequest> request =
     new nsScriptLoadRequest(nullptr, 0,
                             Element::StringToCORSMode(aCrossOrigin));
   request->mURI = aURI;
   request->mIsInline = false;
   request->mLoading = true;
   nsresult rv = StartLoad(request, aType, aScriptFromHead);
   if (NS_FAILED(rv)) {
     return;
   }
   PreloadInfo *pi = mPreloads.AppendElement();
   pi->mRequest = request;
   pi->mCharset = aCharset;
 }
 void
 nsScriptLoader::AddDeferRequest(nsScriptLoadRequest* aRequest)
 {
   mDeferRequests.AppendElement(aRequest);
   if (mDeferEnabled && mDeferRequests.Length() == 1 && mDocument &&
       !mBlockingDOMContentLoaded) {
     MOZ_ASSERT(mDocument->GetReadyStateEnum() == nsIDocument::READYSTATE_LOADING);
     mBlockingDOMContentLoaded = true;
     mDocument->BlockDOMContentLoaded();
   }
 }
 bool
 nsScriptLoader::MaybeRemovedDeferRequests()
 {
   if (mDeferRequests.Length() == 0 && mDocument &&
       mBlockingDOMContentLoaded) {
     mBlockingDOMContentLoaded = false;
     mDocument->UnblockDOMContentLoaded();
     return true;
   }
   return false;
 }

The Tor Browser / annotate

content/base/src/nsScriptLoader.cpp@6474c204b198 (annotated)

content/base/src/nsScriptLoader.cpp