Need to restore old version of asset if updating them is failed..

[harshanvn]

Did a forced update on host files.
After update saw blocked host name count reduced from 62k to 44k. Upon closed inspection saw, below error in the console..

Failed to load resource: the server responded with a status of 503 (Service Unavailable) http://hosts-file.net/.%5Cad_servers.txt

And looking at the host file count..saw below..

[gorhill]

Strange. I can not repro, and code reviewing I can't see where this could happen. The only thing I can think of is that 503 is not considered as an error when using a XHR, and thus the error path was not taken by uMatrix, and thus it ended up loading a 503 web page as a hosts file.

[gorhill]

Fixed with b946a96.

I need to also import the fix in uBlock, this might actually explain why some users report uBlock stopped blocking ads: if EasyList could not be downloaded the same way it happened above to hpHosts, that would cause uBlock to not see the failed request and interpret the error page as a valid EasyList file.

[harshanvn]

I may be completely wrong here. Just throwing my 2 cents here...

if ( typeof this.status === 'number' && this.status >= 200 && this.status < 300 ) {

In the above line of code, i don't see why we need a first condition here. As http status code will always be of type number. Below condition itself may be enough..Sorry if am wrong here..

if ( this.status >= 200 && this.status < 300 ) {

Please see the link below for list of status codes-
* http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

[gorhill]

It's just to be on the safe side in case it is undefined, in which case typeof this.status would return 'undefined'.

Of course I went to look at 503 code spec before the fix...

[harshanvn]

hmm...ok. I am just thinking whether this situation can occur ever, as property type of status should never change. Anywayz, better safe than sorry :)