Handle observing of predisposed signals.

ReactiveKit.podspec

@@ -1,12 +1,12 @@
 Pod::Spec.new do |s|
   s.name             = "ReactiveKit"
-  s.version          = "3.15.3"
+  s.version          = "3.15.4"
   s.summary          = "A Swift Reactive Programming Framework"
   s.description      = "ReactiveKit is a Swift framework for reactive and functional reactive programming."
   s.homepage         = "https://github.com/DeclarativeHub/ReactiveKit"
   s.license          = 'MIT'
   s.author           = { "Srdan Rasic" => "[email protected]" }
-  s.source           = { :git => "https://github.com/DeclarativeHub/ReactiveKit.git", :tag => "v3.15.3" }
+  s.source           = { :git => "https://github.com/DeclarativeHub/ReactiveKit.git", :tag => "v3.15.4" }
 
   s.ios.deployment_target       = '8.0'
   s.osx.deployment_target       = '10.11'

Sources/Observer.swift

@@ -107,7 +107,11 @@ public final class AtomicObserver<Element, Error: Swift.Error>: ObserverProtocol
     public func attach(_ producer: Signal<Element, Error>.Producer) {
         let disposable = producer(self)
         disposablesQueue.async {
-            self.upstreamDisposables.append(disposable)
+            if self.isDisposed {
+                disposable.dispose()
+            } else {
+                self.upstreamDisposables.append(disposable)
+            }
         }
     }
 

Supporting Files/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>3.15.3</string>
+	<string>3.15.4</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>