Merge pull request ReactiveCocoa#1608 from ReactiveCocoa/hot-signal-generator-lifetime

Keep HotSignals alive for as long as their generators are

Author: joshaber

ReactiveCocoa/Swift/ColdSignal.swift

@@ -1163,9 +1163,11 @@ extension ColdSignal {
 				onError = errorHandler
 			}
 
-			return self.self.start(next: { value in
+			self.start(next: { value in
 				sink.put(value)
 			}, error: onError, completed: completionHandler)
+
+			return
 		}
 	}
 }

ReactiveCocoa/Swift/FoundationExtensions.swift

@@ -12,7 +12,7 @@ import LlamaKit
 extension NSNotificationCenter {
 	/// Returns a signal of notifications posted that match the given criteria.
 	public func rac_notifications(name: String? = nil, object: AnyObject? = nil) -> HotSignal<NSNotification> {
-		return HotSignal { sink in
+		return HotSignal.weak { sink in
 			let observer = self.addObserverForName(name, object: object, queue: nil) { notification in
 				sink.put(notification)
 			}