Bug 1403641: Allow data: URI downloads even if data: URI navigations are blocked. r=bz

docshell/base/nsDocShell.cpp

@@ -9967,7 +9967,8 @@ nsDocShell::InternalLoad(nsIURI* aURI,
         aURI,
         contentType,
         aTriggeringPrincipal,
-        (aLoadType == LOAD_NORMAL_EXTERNAL))) {
+        (aLoadType == LOAD_NORMAL_EXTERNAL),
+        !aFileName.IsVoid())) {
     // logging to console happens within AllowTopLevelNavigationToDataURI
     return NS_OK;
   }

dom/security/nsContentSecurityManager.cpp

@@ -26,7 +26,8 @@ nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
   nsIURI* aURI,
   nsContentPolicyType aContentPolicyType,
   nsIPrincipal* aTriggeringPrincipal,
-  bool aLoadFromExternal)
+  bool aLoadFromExternal,
+  bool aIsDownLoad)
 {
   // Let's block all toplevel document navigations to a data: URI.
   // In all cases where the toplevel document is navigated to a
@@ -39,7 +40,7 @@ nsContentSecurityManager::AllowTopLevelNavigationToDataURI(
   if (!mozilla::net::nsIOService::BlockToplevelDataUriNavigations()) {
     return true;
   }
-  if (aContentPolicyType != nsIContentPolicy::TYPE_DOCUMENT) {
+  if (aContentPolicyType != nsIContentPolicy::TYPE_DOCUMENT || aIsDownLoad) {
     return true;
   }
   bool isDataURI =
@@ -590,6 +591,7 @@ nsContentSecurityManager::AsyncOnChannelRedirect(nsIChannel* aOldChannel,
           uri,
           newLoadInfo->GetExternalContentPolicyType(),
           nullTriggeringPrincipal,
+          false,
           false)) {
         // logging to console happens within AllowTopLevelNavigationToDataURI
       aOldChannel->Cancel(NS_ERROR_DOM_BAD_URI);

dom/security/nsContentSecurityManager.h

@@ -35,7 +35,8 @@ public:
   static bool AllowTopLevelNavigationToDataURI(nsIURI* aURI,
                                                nsContentPolicyType aContentPolicyType,
                                                nsIPrincipal* aTriggeringPrincipal,
-                                               bool aLoadFromExternal);
+                                               bool aLoadFromExternal,
+                                               bool aIsDownload);
 
 private:
   static nsresult CheckChannel(nsIChannel* aChannel);