Bug 1312260 - Part 1: Allow access to execCommand("paste") with permission r=bz

MozReview-Commit-ID: B1sfhsQWWQa

--HG--
extra : rebase_source : 533fc39c52733cc9d3f0eb7ff0558dab36f6263d

dom/base/nsContentUtils.cpp

@@ -2076,15 +2076,22 @@ nsContentUtils::CanCallerAccess(nsPIDOMWindowInner* aWindow)
 
 // static
 bool
-nsContentUtils::CallerHasPermission(JSContext* aCx, const nsAString& aPerm)
+nsContentUtils::PrincipalHasPermission(nsIPrincipal* aPrincipal, const nsAString& aPerm)
 {
   // Chrome gets access by default.
-  if (IsSystemCaller(aCx)) {
+  if (IsSystemPrincipal(aPrincipal)) {
     return true;
   }
 
   // Otherwise, only allow if caller is an addon with the permission.
-  return BasePrincipal::Cast(SubjectPrincipal(aCx))->AddonHasPermission(aPerm);
+  return BasePrincipal::Cast(aPrincipal)->AddonHasPermission(aPerm);
+}
+
+// static
+bool
+nsContentUtils::CallerHasPermission(JSContext* aCx, const nsAString& aPerm)
+{
+  return PrincipalHasPermission(SubjectPrincipal(aCx), aPerm);
 }
 
 //static
@@ -6894,12 +6901,11 @@ nsContentUtils::IsRequestFullScreenAllowed(CallerType aCallerType)
 bool
 nsContentUtils::IsCutCopyAllowed(nsIPrincipal* aSubjectPrincipal)
 {
-  if ((!IsCutCopyRestricted() && EventStateManager::IsHandlingUserInput()) ||
-      IsSystemPrincipal(aSubjectPrincipal)) {
+  if (!IsCutCopyRestricted() && EventStateManager::IsHandlingUserInput()) {
     return true;
   }
 
-  return BasePrincipal::Cast(aSubjectPrincipal)->AddonHasPermission(NS_LITERAL_STRING("clipboardWrite"));
+  return PrincipalHasPermission(aSubjectPrincipal, NS_LITERAL_STRING("clipboardWrite"));
 }
 
 /* static */

dom/base/nsContentUtils.h

@@ -503,6 +503,9 @@ public:
   // aWindow can be either outer or inner window.
   static bool CanCallerAccess(nsPIDOMWindowInner* aWindow);
 
+  // Check if the principal is chrome or an addon with the permission.
+  static bool PrincipalHasPermission(nsIPrincipal* aPrincipal, const nsAString& aPerm);
+
   // Check if the JS caller is chrome or an addon with the permission.
   static bool CallerHasPermission(JSContext* aCx, const nsAString& aPerm);
 

dom/html/nsHTMLDocument.cpp

@@ -3201,7 +3201,8 @@ nsHTMLDocument::ExecCommand(const nsAString& commandID,
   }
 
   bool restricted = commandID.LowerCaseEqualsLiteral("paste");
-  if (restricted && !nsContentUtils::IsSystemPrincipal(&aSubjectPrincipal)) {
+  if (restricted && !nsContentUtils::PrincipalHasPermission(&aSubjectPrincipal,
+                                                            NS_LITERAL_STRING("clipboardRead"))) {
     return false;
   }