Ensure observeValueForKeyPath:ofObject:change:context is called consistently.

During the "normal" callback for new and old values, the ofObject:
parameter passed to the observer is the original receiver of the
addObserver:forKeyPath:options:context: call, but that isn't the case
with the call caused by the CPKeyValueObservingOptionInitial option.
This commit uses _targetObject, the receiver of the addObserver:...
call, rather than self, the _CPKVOProxy.

Foundation/CPKeyValueObserving.j

@@ -360,7 +360,7 @@ var kvoNewAndOld = CPKeyValueObservingOptionNew|CPKeyValueObservingOptionOld,
             newValue = [CPNull null];
 
         var changes = [CPDictionary dictionaryWithObject:newValue forKey:CPKeyValueChangeNewKey];
-        [anObserver observeValueForKeyPath:aPath ofObject:self change:changes context:aContext];
+        [anObserver observeValueForKeyPath:aPath ofObject:_targetObject change:changes context:aContext];
     }
 }
 

Tests/AppKit/CPKeyValueObservingTest.j

@@ -0,0 +1,62 @@
+@import <Foundation/CPKeyValueObserving.j>
+
+@implementation CPKeyValueObservingTest : OJTestCase
+{
+    CPString      _lastKeyPath;
+    id            _lastObject;
+    CPDictionary  _lastChange;
+    id            _lastContext;
+}
+
+- (void)setup
+{
+  _lastKeyPath = _lastObject = _lastChange = _lastContext = nil;
+}
+
+- (void)testInitialObserving
+{
+    var tester = [ObservingTester testerWithCheese:@"CHEESE!"];
+    [tester addObserver:self forKeyPath:@"cheese" options:CPKeyValueObservingOptionNew | CPKeyValueObservingOptionInitial context:nil];
+
+    [self assert:@"cheese" equals:_lastKeyPath];
+    [self assert:tester equals:_lastObject];
+    [self assert:[CPDictionary dictionaryWithObject:@"CHEESE!" forKey:CPKeyValueChangeNewKey] equals:_lastChange];
+    [self assert:nil equals:_lastContext];
+}
+
+- (void)observeValueForKeyPath:(CPString)aKeyPath
+                      ofObject:(id)anObject
+                        change:(CPDictionary)aChange
+                       context:(id)aContext
+{
+  _lastKeyPath = aKeyPath;
+  _lastObject  = anObject;
+  _lastChange  = aChange;
+  _lastContext = aContext;
+}
+
+@end
+
+@implementation ObservingTester : CPObject
+{
+    id cheese;
+}
+
++ (id)testerWithCheese:(id)aCheese
+{
+    var tester = [[self alloc] init];
+    [tester setCheese:aCheese];
+    return tester;
+}
+
+- (void)setCheese:(id)aCheese
+{
+    cheese = aCheese;
+}
+
+- (id)cheese
+{
+    return cheese;
+}
+
+@end