I'm creating Firefox addon that registers new protocol which should provide HTML to Firefox from file stored on disk (generated by binary exe).
I have problem with images in tags and (probably) css styles that refer to local file. They aren't load properly and I'm getting a message in the errorconsole like this :
Security Error: Content at moz-nullprincipal:{afde522e-6b29-4359-9959-c46c749687f6} may not load or link to file:///E:/xowa_app/user/anonymous/app/img/file/magnify-clip.png.
My protocol flags : nsIProtocolHandler.URI_IS_LOCAL_FILE | nsIProtocolHandler.URI_IS_LOCAL_RESOURCE | nsIProtocolHandler.URI_STD | nsIProtocolHandler.URI_INHERITS_SECURITY_CONTEXT. (I don't know whether I understand properly MDN reference)
nsIProtocolHandler interface specs need to me that I implement function to creating new channel (MDN) when it is opening URI by the protocol. I create a channel from URI located on disk (html generated by program). The channel has owner property that "grant or deny privileges" and I setted even the owner to system principal who "passes all security checks" (MDN) but the errors are the same.
It seems to that just removing URI_INHERITS_SECURITY_CONTEXT flag (and leaving change owner to system principal) resolves my problem although I don't know when there is need to use this flag.