Squashed commit of the following:

commit 35b4e1abd727ab9a5fb1489d73d4985a18efd138
Author: Mattt Thompson <[email protected]>
Date:   Thu Dec 5 14:22:49 2013 -0800

    Minor formatting

commit 36007b0f147dba1db2d46d26389a76aa339ecf0d
Merge: c25c49a c7ab4ad
Author: Mattt Thompson <[email protected]>
Date:   Thu Dec 5 14:11:40 2013 -0800

    Merge branch 'AFURLConnectionOperation-isFinished-without-being-started-fix' of github.com:sampage/AFNetworking into sampage-AFURLConnectionOperation-isFinished-without-being-started-fix

commit c7ab4ad
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 19:23:48 2013 +1100

    Adds unit tests to cover cancelling an operation before it has begun. Rolls back previous test changes to logic of cancelling after the operation has started.

commit 412d826
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 19:23:01 2013 +1100

    Previous change would mean operations in-flight would not be cancelled. On cancel, check whether the operation is currently executing and if so, cancel the operation immediately.

commit a522bd7
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 18:08:01 2013 +1100

    Updates AFHTTPRequestOperationTests that cover cancelling to adhere to new logic of operations receiving -start after being cancelled

commit fbe385f
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 18:07:02 2013 +1100

    Removing explicit call to set state to AFOperationFinishedState. Happens as a product of cancelConnection and setting here will mean the connection is not cancelled.

commit b71eaa8
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 17:10:23 2013 +1100

    Matching conditionals formatting

commit 270066c
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 16:35:43 2013 +1100

    Checks whether AFURLConnectionOperation isCancelled during start, if so, cancel the connection and mark state as AFOperationFinishedState. Removes connection cancelling call from NSOperation’s cancel method.
    Fixes an issue with iOS 6.1 where cancelling an operation before it had been started would crash after logging “AFHTTPRequestOperation xxx went isFinished=YES without being started by the queue it is in”

commit 72295f6
Author: Sam Page <[email protected]>
Date:   Wed Dec 4 16:31:07 2013 +1100

    Removes cancelled flag from AFURLConnectionOperation, instead relying on the default NSOperation isCancelled.
    Removes KVO notifications for isCancelled flag to adhere to docs: “..Support for cancellation is voluntary but encouraged and your own code should not have to send KVO notifications for this key path..”

Signed-off-by: Mattt Thompson <[email protected]>

Author: sampage

AFNetworking/AFURLConnectionOperation.m

@@ -124,7 +124,6 @@ static inline BOOL AFStateTransitionIsValid(AFOperationState fromState, AFOperat
 
 @interface AFURLConnectionOperation ()
 @property (readwrite, nonatomic, assign) AFOperationState state;
-@property (readwrite, nonatomic, assign, getter = isCancelled) BOOL cancelled;
 @property (readwrite, nonatomic, strong) NSRecursiveLock *lock;
 @property (readwrite, nonatomic, strong) NSURLConnection *connection;
 @property (readwrite, nonatomic, strong) NSURLRequest *request;
@@ -421,7 +420,9 @@ - (BOOL)isConcurrent {
 
 - (void)start {
     [self.lock lock];
-    if ([self isReady]) {
+    if ([self isCancelled]) {
+        [self performSelector:@selector(cancelConnection) onThread:[[self class] networkRequestThread] withObject:nil waitUntilDone:NO modes:[self.runLoopModes allObjects]];
+    } else if ([self isReady]) {
         self.state = AFOperationExecutingState;
 
         [self performSelector:@selector(operationDidStart) onThread:[[self class] networkRequestThread] withObject:nil waitUntilDone:NO modes:[self.runLoopModes allObjects]];
@@ -460,13 +461,11 @@ - (void)finish {
 - (void)cancel {
     [self.lock lock];
     if (![self isFinished] && ![self isCancelled]) {
-        [self willChangeValueForKey:@"isCancelled"];
-        _cancelled = YES;
         [super cancel];
-        [self didChangeValueForKey:@"isCancelled"];
-        
-        // Cancel the connection on the thread it runs on to prevent race conditions
-        [self performSelector:@selector(cancelConnection) onThread:[[self class] networkRequestThread] withObject:nil waitUntilDone:NO modes:[self.runLoopModes allObjects]];
+
+        if ([self isExecuting]) {
+            [self performSelector:@selector(cancelConnection) onThread:[[self class] networkRequestThread] withObject:nil waitUntilDone:NO modes:[self.runLoopModes allObjects]];
+        }
     }
     [self.lock unlock];
 }
@@ -699,7 +698,6 @@ - (id)initWithCoder:(NSCoder *)decoder {
     }
 
     self.state = (AFOperationState)[decoder decodeIntegerForKey:NSStringFromSelector(@selector(state))];
-    self.cancelled = [decoder decodeBoolForKey:NSStringFromSelector(@selector(isCancelled))];
     self.response = [decoder decodeObjectForKey:NSStringFromSelector(@selector(response))];
     self.error = [decoder decodeObjectForKey:NSStringFromSelector(@selector(error))];
     self.responseData = [decoder decodeObjectForKey:NSStringFromSelector(@selector(responseData))];
@@ -723,7 +721,6 @@ - (void)encodeWithCoder:(NSCoder *)coder {
             break;
     }
 
-    [coder encodeBool:[self isCancelled] forKey:NSStringFromSelector(@selector(isCancelled))];
     [coder encodeObject:self.response forKey:NSStringFromSelector(@selector(response))];
     [coder encodeObject:self.error forKey:NSStringFromSelector(@selector(error))];
     [coder encodeObject:self.responseData forKey:NSStringFromSelector(@selector(responseData))];

Tests/Tests/AFHTTPRequestOperationTests.m

@@ -153,6 +153,52 @@ - (void)testThatCancellationOfRequestOperationInvokesFailureCompletionBlock {
     expect(blockError.code).will.equal(NSURLErrorCancelled);
 }
 
+- (void)testThatCancellationOfRequestBeforeStartingRequestSetsError {
+    __block NSError *blockError = nil;
+    
+    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"/delay/5" relativeToURL:self.baseURL]];
+    AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
+    
+    // AFHTTPOperation currently does not have a default response serializer
+    [operation setResponseSerializer:[AFHTTPResponseSerializer serializer]];
+    
+    [operation setCompletionBlockWithSuccess:nil failure:^(AFHTTPRequestOperation *operation, NSError *error) {
+        blockError = error;
+    }];
+    
+    [operation cancel];
+    [operation start];
+    
+    expect([operation isCancelled]).will.beTruthy();
+    expect([operation isFinished]).will.beTruthy();
+    expect([operation isExecuting]).will.beFalsy();
+    
+    expect(operation.error).willNot.beNil();
+    expect(blockError).willNot.beNil();
+    expect(blockError.code).will.equal(NSURLErrorCancelled);
+}
+
+- (void)testThatCancellationOfRequestBeforeStartingRequestSetsErrorInvokesFailureCompletionBlock {
+    __block NSError *blockError = nil;
+    
+    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"/delay/5" relativeToURL:self.baseURL]];
+    AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
+    
+    // AFHTTPOperation currently does not have a default response serializer
+    [operation setResponseSerializer:[AFHTTPResponseSerializer serializer]];
+    
+    [operation setCompletionBlockWithSuccess:nil failure:^(AFHTTPRequestOperation *operation, NSError *error) {
+        blockError = error;
+    }];
+    
+    [operation cancel];
+    [operation start];
+    
+    expect(operation.error).willNot.beNil();
+    expect(blockError).willNot.beNil();
+    expect(blockError.code).will.equal(NSURLErrorCancelled);
+}
+
 - (void)testThat500StatusCodeInvokesFailureCompletionBlockWithErrorOnFailure {
     __block NSError *blockError = nil;