Bug 965413 part 9. Support use of a LoadInfo for javascript: URLs. r=smaug

dom/src/jsurl/nsJSProtocolHandler.cpp

@@ -48,6 +48,7 @@
 #include "nsIContentSecurityPolicy.h"
 #include "nsSandboxFlags.h"
 #include "mozilla/dom/ScriptSettings.h"
+#include "nsILoadInfo.h"
 
 using mozilla::dom::AutoEntryScript;
 
@@ -153,10 +154,16 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel,
     aChannel->GetOwner(getter_AddRefs(owner));
     nsCOMPtr<nsIPrincipal> principal = do_QueryInterface(owner);
     if (!principal) {
-        // No execution without a principal!
-        NS_ASSERTION(!owner, "Non-principal owner?");
-        NS_WARNING("No principal to execute JS with");
-        return NS_ERROR_DOM_RETVAL_UNDEFINED;
+        nsCOMPtr<nsILoadInfo> loadInfo;
+        aChannel->GetLoadInfo(getter_AddRefs(loadInfo));
+        if (loadInfo && loadInfo->GetForceInheritPrincipal()) {
+            principal = loadInfo->LoadingPrincipal();
+        } else {
+            // No execution without a principal!
+            NS_ASSERTION(!owner, "Non-principal owner?");
+            NS_WARNING("No principal to execute JS with");
+            return NS_ERROR_DOM_RETVAL_UNDEFINED;
+        }
     }
 
     nsresult rv;