Fix DateFormatter TimeZone Setter

CoreFoundation/NumberDate.subproj/CFTimeZone.c

@@ -793,7 +793,7 @@ static CFTimeZoneRef __CFTimeZoneCreateSystem(void) {
         size_t zoneInfoDirLen = CFStringGetLength(__tzZoneInfo);
         if (strncmp(linkbuf, tzZoneInfo, zoneInfoDirLen) == 0) {
             name = CFStringCreateWithBytes(kCFAllocatorSystemDefault, (uint8_t *)linkbuf + zoneInfoDirLen,
-                                           strlen(linkbuf) - zoneInfoDirLen + 1, kCFStringEncodingUTF8, false);
+                                           strlen(linkbuf) - zoneInfoDirLen, kCFStringEncodingUTF8, false);
         } else {
             name = CFStringCreateWithBytes(kCFAllocatorSystemDefault, (uint8_t *)linkbuf, strlen(linkbuf), kCFStringEncodingUTF8, false);
         }

Foundation/DateFormatter.swift

@@ -176,13 +176,13 @@ open class DateFormatter : Formatter {
     /*@NSCopying*/ internal var _timeZone: TimeZone? { willSet { _reset() } }
     open var timeZone: TimeZone! {
         get {
-            guard let timeZone = _timeZone else {
+            guard let tz = _timeZone else {
                 return (CFDateFormatterCopyProperty(_cfObject, kCFDateFormatterTimeZone) as! NSTimeZone)._swiftObject
             }
-            return timeZone
+            return tz
         }
         set {
-            _timeZone = timeZone
+            _timeZone = newValue
         }
     }
 

TestFoundation/TestDateFormatter.swift

@@ -24,6 +24,8 @@ class TestDateFormatter: XCTestCase {
             ("test_dateFormatString", test_dateFormatString),
             ("test_setLocaleToNil", test_setLocaleToNil),
             ("test_setTimeZoneToNil", test_setTimeZoneToNil),
+            ("test_setTimeZone", test_setTimeZone),
+            ("test_ExpectedTimeZone", test_ExpectedTimeZone),
         ]
     }
 
@@ -356,4 +358,54 @@ class TestDateFormatter: XCTestCase {
         // Time zone should go back to the system one.
         XCTAssertEqual(f.timeZone, NSTimeZone.system)
     }
+
+    func test_setTimeZone() {
+        // Test two different time zones. Should ensure that if one
+        // happens to be TimeZone.current, we still get a valid test.
+        let newYork = TimeZone(identifier: "America/New_York")!
+        let losAngeles = TimeZone(identifier: "America/Los_Angeles")!
+
+        XCTAssertNotEqual(newYork, losAngeles)
+
+        // Case 1: New York
+        let f = DateFormatter()
+        f.timeZone = newYork
+        XCTAssertEqual(f.timeZone, newYork)
+
+        // Case 2: Los Angeles
+        f.timeZone = losAngeles
+        XCTAssertEqual(f.timeZone, losAngeles)
+    }
+
+    func test_ExpectedTimeZone() {
+        let gmt = TimeZone(abbreviation: DEFAULT_TIMEZONE)
+        let newYork = TimeZone(identifier: "America/New_York")!
+        let losAngeles = TimeZone(identifier: "America/Los_Angeles")!
+
+        XCTAssertNotEqual(newYork, losAngeles)
+
+        let now = Date()
+
+        let f = DateFormatter()
+        f.dateFormat = "z"
+
+        // Case 1: TimeZone.current
+        f.timeZone = TimeZone.current
+        XCTAssertEqual(f.string(from: now), f.timeZone.abbreviation())
+
+        // Case 2: New York
+        f.timeZone = newYork
+        XCTAssertEqual(f.string(from: now), f.timeZone.abbreviation())
+
+        // Case 3: Los Angeles
+        f.timeZone = losAngeles
+        XCTAssertEqual(f.string(from: now), f.timeZone.abbreviation())
+
+        guard gmt != TimeZone.current else {
+            print("Inconclusive: This test checks to see if the formatter produces the same TZ as TimeZone.current")
+            print("When it fails, TimeZone.current formats as GMT instead of normal.")
+            print("Unfortunately, we can't use GMT as TimeZone.current for this test to be conclusive.")
+            return
+        }
+    }
 }