Fix disposing of CancellationTokenSource with registrations.

Author: nlutsenko

Bolts/Common/BFCancellationToken.m

@@ -124,11 +124,9 @@ - (void)dispose {
         if (self.disposed) {
             return;
         }
+        [self.registrations makeObjectsPerformSelector:@selector(dispose)];
+        self.registrations = nil;
         self.disposed = YES;
-        for (BFCancellationTokenRegistration *registration in self.registrations) {
-            [registration dispose];
-        }
-        [self.registrations removeAllObjects];
     }
 }
 

BoltsTests/CancellationTests.m

@@ -79,4 +79,12 @@ - (void)testDispose {
     XCTAssertThrowsSpecificNamed(cts.token.cancellationRequested, NSException, NSInternalInconsistencyException);
 }
 
+- (void)testDisposeRegistrationBeforeCancellationToken {
+    BFCancellationTokenSource *cts = [BFCancellationTokenSource cancellationTokenSource];
+    BFCancellationTokenRegistration *registration = [cts.token registerCancellationObserverWithBlock:^{ }];
+
+    [cts dispose];
+    XCTAssertNoThrow([registration dispose]);
+}
+
 @end