Reject invalid URIs in fs: handler

- closes #83

Author: lidel

lib/protocols.js

@@ -118,6 +118,12 @@ CommonProtocolHandler.prototype = Object.freeze({
       channel = ioservice.newChannelFromURI(httpUri)
     }
 
+    // fs: handler should reject non-ipfs URIs
+    if (!isIPFS.url(httpUri.spec)) {
+      channel.cancel(Cr.NS_ERROR_MALFORMED_URI)
+      return channel
+    }
+
     if (gw.fsUris && this.scheme === FS_SCHEME) {
       channel.originalURI = aURI
       channel.loadFlags &= ~Ci.nsIChannel.LOAD_REPLACE