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[tor-commits] [torbutton/master] Bug 9901: Fix freeze due to content type sniffing
commit d7cb80eac503791f9026b7ce21bcaedd72d6181c
Author: Georg Koppen <gk@xxxxxxxxxxxxxx>
Date: Wed Feb 12 12:54:08 2014 +0100
Bug 9901: Fix freeze due to content type sniffing
The external application blocker code suppresses error messages that are
triggered by the JS -> C++ bridge. The downside is that content type
sniffing leads to browser freezes. This patch overrides Firefox methods
in order to gain the former while avoiding the latter.
---
src/chrome/content/torbutton.js | 100 ++++++++++++++++++++++++++++++++
src/components/external-app-blocker.js | 24 ++------
2 files changed, 106 insertions(+), 18 deletions(-)
diff --git a/src/chrome/content/torbutton.js b/src/chrome/content/torbutton.js
index 1f8e82c..f2fcb77 100644
--- a/src/chrome/content/torbutton.js
+++ b/src/chrome/content/torbutton.js
@@ -6,6 +6,13 @@
// TODO: Double-check there are no strange exploits to defeat:
// http://kb.mozillazine.org/Links_to_local_pages_don%27t_work
+XPCOMUtils.defineLazyModuleGetter(this, "HUDService",
+ "resource:///modules/HUDService.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "ConsoleServiceListener",
+ "resource://gre/modules/devtools/WebConsoleUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "WebConsoleUtils",
+ "resource://gre/modules/devtools/WebConsoleUtils.jsm");
+
const k_tb_browser_update_needed_pref = "extensions.torbutton.updateNeeded";
const k_tb_tor_check_failed_topic = "Torbutton:TorCheckFailed";
@@ -2514,12 +2521,104 @@ function torbutton_is_windowed(wind) {
return true;
}
+// This is the console observer used for getting unwanted error messages
+// resulting from JS -> C++ transition filtered out.
+var consoleObserver = {
+
+ obs : null,
+
+ register: function() {
+ this.obs = Cc["@mozilla.org/observer-service;1"].
+ getService(Ci.nsIObserverService);
+ this.obs.addObserver(this, "web-console-created", false);
+ },
+
+ unregister: function() {
+ if (this.obs) {
+ this.obs.removeObserver(this, "web-console-created");
+ }
+ },
+
+ observe: function(subject, topic, data) {
+ if (topic === "web-console-created") {
+ var id = subject.QueryInterface(Ci.nsISupportsString).toString();
+ var con = HUDService.getHudReferenceById(subject);
+ con.ui.reportPageErrorOld = con.ui.reportPageError;
+ // Filtering the messages by making them hidden adding the
+ // "hidden-message" class. If the message does not need to get filtered
+ // the original method is executed without any modifications.
+ con.ui.reportPageError =
+ function WCF_reportPageError(aCategory, aScriptError) {
+ var message = aScriptError.errorMessage;
+ if (message && message.indexOf("NS_ERROR_NOT_AVAILABLE") > -1 &&
+ message.indexOf("external-app-blocker.js") > -1) {
+ return this.reportPageErrorOld(aCategory, aScriptError).classList.
+ add("hidden-message");
+ } else {
+ return this.reportPageErrorOld(aCategory, aScriptError);
+ }
+ }
+ }
+ }
+};
+
+// Ideally, we only need to patch/override one method to avoid errors showing up
+// in the browser console. Alas, that is not as easy given the presence of
+// cached messages and the Web Console which we need to consider as well while
+// overriding Devtool methods. Thus, we patch the code path that is called when
+// the browser console is already open AND additionally the one when cached
+// messages are displayed.
+function handleConsole() {
+ consoleObserver.register();
+ try {
+ // Filtering using the "web-console-created" notification is not enough as
+ // the cached messages are already loaded when it is fired. Therefore,
+ // change |getCachedMessages()| slighty to fit the needs at hand.
+ // The original code is https://mxr.mozilla.org/mozilla-esr24/source/
+ // toolkit/devtools/webconsole/WebConsoleUtils.jsm#998 ff. and distributed
+ // under the MPL 2.0 license.
+ ConsoleServiceListener.prototype.getCachedMessages =
+ function CSL_getCachedMessages(aIncludePrivate = false) {
+ var innerWindowID = this.window ? WebConsoleUtils.
+ getInnerWindowId(this.window) : null;
+ var errors = Services.console.getMessageArray() || [];
+
+ return errors.filter((aError) => {
+ if (aError instanceof Ci.nsIScriptError) {
+ var message = aError.message;
+ if (message && message.indexOf("NS_ERROR_NOT_AVAILABLE") > -1 &&
+ message.indexOf("external-app-blocker.js") > -1) {
+ return false;
+ }
+ if (!aIncludePrivate && aError.isFromPrivateWindow) {
+ return false;
+ }
+ if (innerWindowID &&
+ (aError.innerWindowID != innerWindowID ||
+ !this.isCategoryAllowed(aError.category))) {
+ return false;
+ }
+ }
+ else if (innerWindowID) {
+ // If this is not an nsIScriptError and we need to do window-based
+ // filtering we skip this message.
+ return false;
+ }
+
+ return true;
+ });
+ };
+ } catch (e) {}
+}
+
// Bug 1506 P3: This is needed pretty much only for the version check
// and the window resizing. See comments for individual functions for
// details
function torbutton_new_window(event)
{
torbutton_log(3, "New window");
+ // Working around #9901, sigh...
+ handleConsole();
var browser = getBrowser();
if(!browser) {
@@ -2558,6 +2657,7 @@ function torbutton_new_window(event)
function torbutton_close_window(event) {
torbutton_window_pref_observer.unregister();
torbutton_tor_check_observer.unregister();
+ consoleObserver.unregister();
// TODO: This is a real ghetto hack.. When the original window
// closes, we need to find another window to handle observing
diff --git a/src/components/external-app-blocker.js b/src/components/external-app-blocker.js
index 1996179..057f4ae 100644
--- a/src/components/external-app-blocker.js
+++ b/src/components/external-app-blocker.js
@@ -122,24 +122,12 @@ ExternalWrapper.prototype =
var call;
if(params.length) call = "("+params.join().replace(/(?:)/g,function(){return "p"+(++x)})+")";
else call = "()";
- if(method == "getTypeFromFile" || method == "getTypeFromExtension" || method == "getTypeFromURI") {
- // XXX: Due to https://developer.mozilla.org/en/Exception_logging_in_JavaScript
- // this is necessary to prevent error console noise on the return to C++ code.
- // It is not technically correct, but as far as I can tell, returning null
- // here should be equivalent to throwing an error for the codepaths invovled
- var fun = "(function "+call+"{"+
- "if (arguments.length < "+wrapped[method].length+")"+
- " throw Components.results.NS_ERROR_XPC_NOT_ENOUGH_ARGS;"+
- "try { return wrapped."+method+".apply(wrapped, arguments); }"+
- "catch(e) { if(e.result == Components.results.NS_ERROR_NOT_AVAILABLE) return null; else throw e;} })";
- newObj[method] = eval(fun);
- } else {
- var fun = "(function "+call+"{"+
- "if (arguments.length < "+wrapped[method].length+")"+
- " throw Components.results.NS_ERROR_XPC_NOT_ENOUGH_ARGS;"+
- "return wrapped."+method+".apply(wrapped, arguments);})";
- newObj[method] = eval(fun);
- }
+
+ var fun = "(function "+call+"{"+
+ "if (arguments.length < "+wrapped[method].length+")"+
+ " throw Components.results.NS_ERROR_XPC_NOT_ENOUGH_ARGS;"+
+ "return wrapped."+method+".apply(wrapped, arguments);})";
+ newObj[method] = eval(fun);
} else {
newObj.__defineGetter__(method, function() { return wrapped[method]; });
newObj.__defineSetter__(method, function(val) { wrapped[method] = val; });
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