HandlerPageView: Prevent viewing older revisions if not allowed

handlers/handlerpageview.cpp

@@ -90,6 +90,10 @@ Response HandlerPageView::handleRequest(PageDao &pageDao, std::string pagename,
 	{
 		if(revisionid > 0)
 		{
+			if(!effectivePermissions(pagename).canSeePageHistory())
+			{
+				return errorResponse("Error", "You are not allowed to view older revisions of this page");
+			}
 			revision = this->database->createRevisionDao()->getRevisionForPage(pagename, revisionid);
 			if(!revision)
 			{