799470 - pac file dnsResolve() should return null on fail

Status: RESOLVED FIXED

(Core :: Networking: HTTP, defect)

Description

[Patrick McManus [:mcmanus]]

in bug 795597 matti provides this pac file that isn't working for two reasons.

function FindProxyForURL(url, host){

if (isResolvable("nonexistant.lan"))
    
{
return "DIRECT";
}

else {
alert(myIpAddress()); 
return "SOCKS5 127.0.0.1:8080";
}
}

one reason is that isResolvable(foo) calls dnsResolve(foo) which was, when unable to resolve foo, was returning a function failure instead of null which is the backwards compatible thing to do.

Comment 1

[Patrick McManus [:mcmanus]]

Attachment: patch 0

Comment 2

[Patrick McManus [:mcmanus]]

  https://hg.mozilla.org/integration/mozilla-inbound/rev/1c6b5cae9dc1

Comment 3

[Patrick McManus [:mcmanus]]

Comment on attachment 669609 [details] [diff] [review]
patch 0

[Approval Request Comment]
Bug caused by (feature/regressing bug #): jank killing proxy rewrite 769764
User impact if declined: PAC files relying on negative dnsResolve() or isHostResolvable() behavior will have compatibility problems
Testing completed (on m-c, etc.): manual testing, xpcshell coverage, confirmation with a handful of in the wild examples
Risk to taking this patch (and alternatives if risky): extremely low.
String or UUID changes made by this patch: none

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/1c6b5cae9dc1

Comment 5

[bhavana bajaj [:bajaj]]

Comment on attachment 669609 [details] [diff] [review]
patch 0

Approving for aurora as the latest nightly with this patch confirms to fix bug 795597 tracked for 18 and the patch itself is low risk .

Comment 6

[Patrick McManus [:mcmanus]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/561916b7f5f1