Bug 86193

Add a preference allowing users to prevent sites from cancelling the contextmenu event, so right click will always bring up a context menu if the pref is set.
r=jst sr=bryner

content/base/public/nsContentUtils.h

@@ -286,11 +286,11 @@ public:
                                        nsINodeInfoManager* aNodeInfoManager,
                                        nsINodeInfo** aNodeInfo);
 
-private:
   static nsresult GetDocumentAndPrincipal(nsIDOMNode* aNode,
                                           nsIDocument** aDocument,
                                           nsIPrincipal** aPrincipal);
 
+private:
   static nsresult doReparentContentWrapper(nsIContent *aChild,
                                            nsIDocument *aNewDocument,
                                            nsIDocument *aOldDocument,

content/xul/content/src/Makefile.in

@@ -47,6 +47,7 @@ REQUIRES	= xpcom \
 		  xultmpl \
 		  webshell \
 		  view \
+		  pref \
 		  $(NULL)
 
 CPPSRCS		= \

content/xul/content/src/nsXULPopupListener.cpp

@@ -56,6 +56,7 @@
 #include "nsIDOMMouseListener.h"
 #include "nsIDOMContextMenuListener.h"
 #include "nsContentCID.h"
+#include "nsContentUtils.h"
 
 #include "nsIScriptGlobalObject.h"
 #include "nsIScriptContext.h"
@@ -67,6 +68,11 @@
 #include "nsIDOMNSUIEvent.h"
 #include "nsIDOMEventTarget.h"
 #include "nsIDOMNSEvent.h"
+#include "nsIPrefService.h"
+#include "nsIPrefBranch.h"
+#include "nsIServiceManagerUtils.h"
+#include "nsIPrincipal.h"
+#include "nsIScriptSecurityManager.h"
 
 #include "nsIBoxObject.h"
 #include "nsIPopupBoxObject.h"
@@ -218,19 +224,53 @@ XULPopupListenerImpl::PreLaunchPopup(nsIDOMEvent* aMouseEvent)
     return NS_OK;
   }
 
+  // Get the node that was clicked on.
+  nsCOMPtr<nsIDOMEventTarget> target;
+  mouseEvent->GetTarget(getter_AddRefs(target));
+  nsCOMPtr<nsIDOMNode> targetNode = do_QueryInterface(target);
+
   PRBool preventDefault;
   nsUIEvent->GetPreventDefault(&preventDefault);
+  if (preventDefault && targetNode && popupType == eXULPopupType_context) {
+    // Someone called preventDefault on a context menu.
+    // Let's make sure they are allowed to do so.
+    nsCOMPtr<nsIPrefService> prefService =
+      do_GetService(NS_PREFSERVICE_CONTRACTID);
+
+    NS_ENSURE_TRUE(prefService, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsIPrefBranch> prefBranch;
+    prefService->GetBranch(nsnull, getter_AddRefs(prefBranch));
+
+    PRBool eventEnabled;
+    nsresult rv = prefBranch->GetBoolPref("dom.event.contextmenu.enabled",
+                                          &eventEnabled);
+    if (NS_SUCCEEDED(rv) && !eventEnabled) {
+      // The user wants his contextmenus.  Let's make sure that this is a website
+      // and not chrome since there could be places in chrome which don't want
+      // contextmenus.
+      nsCOMPtr<nsIDocument> doc;
+      nsCOMPtr<nsIPrincipal> prin;
+      nsContentUtils::GetDocumentAndPrincipal(targetNode,
+                                              getter_AddRefs(doc),
+                                              getter_AddRefs(prin));
+      if (prin) {
+        nsCOMPtr<nsIPrincipal> system;
+        nsContentUtils::GetSecurityManager()->GetSystemPrincipal(getter_AddRefs(system));
+        if (prin != system) {
+          // This isn't chrome.  Cancel the preventDefault() and
+          // let the event go forth.
+          preventDefault = PR_FALSE;
+        }
+      }
+    }
+  }
+
   if (preventDefault) {
     // someone called preventDefault. bail.
     return NS_OK;
   }
 
-  // Get the node that was clicked on.
-  nsCOMPtr<nsIDOMEventTarget> target;
-  mouseEvent->GetTarget( getter_AddRefs( target ) );
-  nsCOMPtr<nsIDOMNode> targetNode;
-  if (target) targetNode = do_QueryInterface(target);
-
   // This is a gross hack to deal with a recursive popup situation happening in AIM code. 
   // See http://bugzilla.mozilla.org/show_bug.cgi?id=96920.
   // If a menu item child was clicked on that leads to a popup needing

modules/libpref/src/init/all.js

@@ -416,6 +416,8 @@ pref("dom.disable_open_during_load",                false);
 pref("dom.popup_maximum",                           20);
 pref("dom.popup_allowed_events", "change click dblclick error reset submit");
 
+pref("dom.event.contextmenu.enabled",       true);
+
 pref("javascript.enabled",                  true);
 pref("javascript.allow.mailnews",           false);
 pref("javascript.options.strict",           false);