Fixed strict bool matching in JSONEncoder

Author: bubski

Foundation/JSONEncoder.swift

@@ -1615,27 +1615,15 @@ extension _JSONDecoder {
         guard let value = value else { return nil }
         guard !(value is NSNull) else { return nil }
 
-        //        if let number = value as? NSNumber {
-        //            // TODO: Add a flag to coerce non-boolean numbers into Bools?
-        //            if number === kCFBooleanTrue as NSNumber {
-        //                return true
-        //            } else if number === kCFBooleanFalse as NSNumber {
-        //                return false
-        //            }
-        //
-        //            /* FIXME: If swift-corelibs-foundation doesn't change to use NSNumber, this code path will need to be included and tested:
-        //             } else if let bool = value as? Bool {
-        //             return bool
-        //             */
-        //
-        //        }
-        //
-        //        throw DecodingError._typeMismatch(at: self.codingPath, expectation: type, reality: value)
-
         guard let number = value as? NSNumber else {
             throw DecodingError._typeMismatch(at: self.codingPath, expectation: type, reality: value)
         }
 
+        // TODO: Add a flag to coerce non-boolean numbers into Bools?
+        guard number._objCType == .Bool else {
+            throw DecodingError._typeMismatch(at: self.codingPath, expectation: type, reality: value)
+        }
+
         let bool = number.boolValue
         guard NSNumber(value: bool) == number else {
             throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: self.codingPath, debugDescription: "Parsed JSON number <\(number)> does not fit in \(type)."))

TestFoundation/TestJSONEncoder.swift

@@ -321,6 +321,12 @@ class TestJSONEncoder : XCTestCase {
     // MARK: - Test encoding and decoding of built-in Codable types
     func test_codingOfBool() {
         test_codingOf(value: Bool(true), toAndFrom: "true")
+        test_codingOf(value: Bool(false), toAndFrom: "false")
+
+        do {
+            _ = try JSONDecoder().decode([Bool].self, from: "[1]".data(using: .utf8)!)
+            XCTFail("Coercing non-boolean numbers into Bools was expected to fail")
+        } catch { }
     }
 
     func test_codingOfInt8() {