Reference (spec-faithful, no quirks)
Helper library
The checker runs this engine's own PAC helper library, copied verbatim at 3f73c528a1ae (MPL-2.0).
Upstream source.
Version ranges and quirks
Later ranges list only what changes compared with the range before.
Reference (all)
Spec-faithful baseline without engine quirks; not a real product.
| Behaviour | Value | Source |
|---|
| alert() output | console | doc, verified 2026-10-04 |
|---|
| Non-ASCII result rejected | false | doc, verified 2026-10-04 |
|---|
| DNS lookups | sync
Answers come only from your DNS table; a host that is not listed is unresolvable. | doc, verified 2026-10-04 |
|---|
| dnsResolve is IPv4 only | false
dnsResolve returns the DNS table value as given. | doc, verified 2026-10-04 |
|---|
| JavaScript level accepted | latest | doc, verified 2026-10-04 |
|---|
| Calls FindProxyForURLEx if defined | false | doc, verified 2026-10-04 |
|---|
| Microsoft *Ex functions | false
Microsoft *Ex extensions are not part of the Netscape specification. | doc, verified 2026-10-04 |
|---|
| Global variables persist between calls | true | doc, verified 2026-10-04 |
|---|
| Host lower-cased by the engine | false | doc, verified 2026-10-04 |
|---|
| myIpAddress() source | user_supplied | doc, verified 2026-10-04 |
|---|
| Native (C++) bindings | dnsResolve, myIpAddress, alert
The PAC functions come from the helper library, not from native bindings. | doc, verified 2026-10-04 |
|---|
| On exception | error | doc, verified 2026-10-04 |
|---|
| On non-string / undefined result | error | doc, verified 2026-10-04 |
|---|
| URL passed to FindProxyForURL | none | doc, verified 2026-10-04 |
|---|
Function availability