Fix web-based protocol handlers not working from Send Link and certain other situations (bug 394483), r=biesi, r=gavin (browser portion), sr=sicking, a=beta blocker

browser/base/content/browser.js

@@ -3941,6 +3941,10 @@ nsBrowserAccess.prototype =
       return null;
     }
 
+    if (!gPrefService)
+      gPrefService = Components.classes["@mozilla.org/preferences-service;1"]
+                               .getService(Components.interfaces.nsIPrefBranch2);
+
     var loadflags = isExternal ?
                        Ci.nsIWebNavigation.LOAD_FLAGS_FROM_EXTERNAL :
                        Ci.nsIWebNavigation.LOAD_FLAGS_NONE;

netwerk/mime/public/nsIMIMEInfo.idl

@@ -114,11 +114,8 @@ interface nsIHandlerInfo : nsISupports {
      *
      * @param aWindowContext 
      *        The window to parent the dialog against, and, if a web handler
-     *        is chosen, it is loaded in this window as well.  This parameter
-     *        may be ultimately passed nsIURILoader.openURI in the case of a
-     *        web handler, and aWindowContext is null or not present, web
-     *        handlers will fail.  We need to do better than that; bug 394483
-     *        filed in order to track.
+     *        is chosen, it is loaded in this window as well.  See 
+     *        nsIHandlerApp.launchWithURI for more details.
      *
      * @throw NS_ERROR_INVALID_ARG if preferredAction is not valid for this
      * call. Other exceptions may be thrown.
@@ -279,9 +276,16 @@ interface nsIHandlerApp : nsISupports {
      *        The URI to launch this application with
      *
      * @param aWindowContext 
-     *        Required for web handlers; is passed through to 
-     *        nsIURILoader.openURI, but see bug 394483 for info on 
-     *        how this needs to evolve.
+     *
+     *        Currently only relevant to web-handler apps.  If given, this
+     *        represents the docshell to load the handler in and is passed
+     *        through to nsIURILoader.openURI.  If this parameter is null or
+     *        not present, the web handler app implementation will attempt to 
+     *        find/create a place to load the handler and do so.  As of this
+     *        writing, it tries to load the web handler in a new window using
+     *        nsIBrowserDOMWindow.openURI.  In the future, it may attempt to 
+     *        have a more comprehensive strategy which could include handing
+     *        off to the system default browser (bug 394479).
      */
     void launchWithURI(in nsIURI aURI, 
                        [optional] in nsIInterfaceRequestor aWindowContext);

uriloader/exthandler/nsWebHandlerApp.js

@@ -44,6 +44,7 @@ Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 
 const Ci = Components.interfaces;
 const Cr = Components.results;
+const Cc = Components.classes;
 
 ////////////////////////////////////////////////////////////////////////////////
 //// nsWebHandler class
@@ -95,24 +96,61 @@ nsWebHandlerApp.prototype = {
     // encode the URI to be handled
     var escapedUriSpecToHandle = encodeURIComponent(aURI.spec);
 
-    // insert the encoded URI 
-    var uriToSend = this.uriTemplate.replace("%s", escapedUriSpecToHandle);
+    // insert the encoded URI and create the object version 
+    var uriSpecToSend = this.uriTemplate.replace("%s", escapedUriSpecToHandle);
+    var ioService = Cc["@mozilla.org/network/io-service;1"].
+                    getService(Ci.nsIIOService);
+    var uriToSend = ioService.newURI(uriSpecToSend, null, null);
+    
+    // if we have a window context, use the URI loader to load there
+    if (aWindowContext) {
 
       // create a channel from this URI
-    var ioService = Components.classes["@mozilla.org/network/io-service;1"].
-                    getService(Components.interfaces.nsIIOService);
-    var channel = ioService.newChannel(uriToSend, null, null);
-    channel.loadFlags = Components.interfaces.nsIChannel.LOAD_DOCUMENT_URI;
+      var channel = ioService.newChannelFromURI(uriToSend);
+      channel.loadFlags = Ci.nsIChannel.LOAD_DOCUMENT_URI;
 
       // load the channel
-    var uriLoader = Components.classes["@mozilla.org/uriloader;1"].
-                    getService(Components.interfaces.nsIURILoader);
+      var uriLoader = Cc["@mozilla.org/uriloader;1"].
+                      getService(Ci.nsIURILoader);
       // XXX ideally, aIsContentPreferred (the second param) should really be
       // passed in from above.  Practically, true is probably a reasonable
       // default since browsers don't care much, and link click is likely to be
       // the more interesting case for non-browser apps.  See 
       // <https://bugzilla.mozilla.org/show_bug.cgi?id=392957#c9> for details.
       uriLoader.openURI(channel, true, aWindowContext);
+      return;
+    } 
+
+    // since we don't have a window context, hand it off to a browser
+    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
+      getService(Ci.nsIWindowMediator);
+
+    // get browser dom window
+    var browserDOMWin = windowMediator.getMostRecentWindow("navigator:browser")
+                        .QueryInterface(Ci.nsIDOMChromeWindow)
+                        .browserDOMWindow;
+
+    // if we got an exception, there are several possible reasons why:
+    // a) this gecko embedding doesn't provide an nsIBrowserDOMWindow
+    //    implementation (i.e. doesn't support browser-style functionality),
+    //    so we need to kick the URL out to the OS default browser.  This is
+    //    the subject of bug 394479.
+    // b) this embedding does provide an nsIBrowserDOMWindow impl, but
+    //    there doesn't happen to be a browser window open at the moment; one
+    //    should be opened.  It's not clear whether this situation will really
+    //    ever occur in real life.  If it does, the only API that I can find
+    //    that seems reasonably likely to work for most embedders is the
+    //    command line handler.  
+    // c) something else went wrong 
+    //
+    // it's not clear how one would differentiate between the three cases
+    // above, so for now we don't catch the exception
+
+    // openURI
+    browserDOMWin.openURI(uriToSend,
+                          null, // no window.opener 
+                          Ci.nsIBrowserDOMWindow.OPEN_DEFAULT_WINDOW,
+                          Ci.nsIBrowserDOMWindow.OPEN_NEW);
       
     return;
   },

uriloader/exthandler/tests/mochitest/handlerApp.xhtml

@@ -12,11 +12,17 @@ Pseudo Web Handler App
 <![CDATA[
 function onLoad() {
 
-	var originalUriToHandle = encodeURIComponent(window.opener.testURI); 
-    
-  window.opener.is(location.search, "?uri=" + originalUriToHandle,
+  // if we have a window.opener, this must be the windowContext
+  // instance of this test.  check that we got the URI right and clean up.
+  if (window.opener) {
+    window.opener.is(location.search, 
+                     "?uri=" + encodeURIComponent(window.opener.testURI), 
                      "uri passed to web-handler app");
-  window.opener.SimpleTest.finish() 
+    window.opener.SimpleTest.finish();
+  } 
+
+  // ensure that we actually have the privs to close non-script-opened windows
+  netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect'); 
   window.close();
 }
 ]]>

uriloader/exthandler/tests/mochitest/handlerApps.js

@@ -65,9 +65,15 @@ function test() {
  
   webHandler.launchWithURI(uri, windowContext); 
 
-  // if we get this far without an exception, we've passed
-  ok(true, "webHandler launchWithURI test");
+  // if we get this far without an exception, we've at least partly passed
+  // (remaining check in handlerApp.xhtml)
+  ok(true, "webHandler launchWithURI (existing window/tab) started");
 
+  // make the web browser launch in its own window/tab
+  webHandler.launchWithURI(uri);
+  
+  // if we get this far without an exception, we've passed
+  ok(true, "webHandler launchWithURI (new window/tab) test started");
 
   // set up the local handler object
   var localHandler =