Rect: correct equality implementation

Equality for Rect needs to take into account standardization of the rectangle.  This adjusts the implementation accordingly.  In order to account for the recursion between `isNull`, `standardized` and `==`, extract a comparator for `Rect`.

Author: rjallanreal

Sources/SwiftWin32/CG/Rect.swift

@@ -206,11 +206,23 @@ public struct Rect {
 
   /// Returns whether the rectangle is equal to the null rectangle.
   public var isNull: Bool {
-    return self == .null
+    return self.pureEqualityCheck(.null)
+  }
+
+  @inline(__always) private func pureEqualityCheck(_ rhs: Rect) 
+      -> Bool {
+    return (self.origin == rhs.origin) && (self.size == rhs.size)
   }
 }
 
+
+
 extension Rect: Equatable {
+  // MARK - Operator Functions
+  public static func == (lhs: Rect, rhs: Rect) -> Bool {
+    let lhs: Rect = lhs.standardized, rhs: Rect = rhs.standardized
+    return lhs.pureEqualityCheck(rhs)
+  }
 }
 
 extension Rect: CustomDebugStringConvertible {

Tests/CoreGraphicsTests/CoreGraphicsTests.swift

@@ -203,6 +203,19 @@ final class CoreGraphicsTests: XCTestCase {
     XCTAssertFalse(r4.intersects(r1))
   }
 
+  func testRectNonstandardEquality() {
+    let r1: Rect = Rect(x: 0, y: 0, width: 10, height: 10)
+    let r2: Rect = Rect(x: 10, y: 10, width: -10, height: -10)
+    let r3: Rect = Rect(x: 10, y: 10, width: -9.9, height: -10)
+
+    XCTAssertTrue(r1 == r2)
+    XCTAssertFalse(r2 == r3)
+
+    let null1: Rect = Rect.null
+    let null2: Rect = Rect.null
+    XCTAssertTrue(null1 == null2)
+  }
+
   static var allTests = [
     ("testAffineTransformIdentity", testAffineTransformIdentity),
     ("testAffineTransformIdentityIsIdentity", testAffineTransformIdentityIsIdentity),
@@ -216,5 +229,6 @@ final class CoreGraphicsTests: XCTestCase {
     ("testRectInsetBy", testRectInsetBy),
     ("testRectIntersection", testRectIntersection),
     ("testRectIntersects", testRectIntersects),
+    ("testRectNonstandardEquality", testRectNonstandardEquality),
   ]
 }