[SR-6396] URLSessionConfiguration has `isDiscretionary` on iOS, `discretionary` on Linux

[swift-ci]

Previous ID	SR-6396
Radar	rdar://35551732
Original Reporter	p_thompson (JIRA User)
Type	Bug
Status	Resolved
Resolution	Done

Environment

Linux w/ Swift 4

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug
Assignee	iothmane (JIRA)
Priority	Medium

md5: 399753fafb226b6f493973bc33872d9f

Issue Description:

When using a URLSessionConfiguration, I expected to be able to set discretionary transfers with .isDiscretionary. On Darwin platforms, this works as expect. On Linux, this field doesn't exist and is instead .discretionary. This seems like a needless difference.

import Foundation
let configuration = URLSessionConfiguration()

let aMirror = Mirror(reflecting: configuration)

for (label, value) in aMirror.children {
print("(label!): (value)")
}

https://swift.sandbox.bluemix.net/#/repl

Swift Ver. 3.1.1 (Release) // repros on orchard with 4.0 too
Platform: Linux (x86_64)

identifier: nil
requestCachePolicy: useProtocolCachePolicy
timeoutIntervalForRequest: 60.0
timeoutIntervalForResource: 604800.0
networkServiceType: default
allowsCellularAccess: true

discretionary: false

connectionProxyDictionary: nil
httpShouldUsePipelining: false
httpShouldSetCookies: true
httpCookieAcceptPolicy: onlyFromMainDocumentDomain
httpAdditionalHeaders: nil
httpMaximumConnectionsPerHost: 6
httpCookieStorage: nil
urlCredentialStorage: nil
urlCache: nil
shouldUseExtendedBackgroundIdleMode: false
protocolClasses: nil

[swift-ci]

Comment by Othmane (JIRA)

Possible fix here: #1589

[spevans]

This has been merged into the master branch