improve deinit for the dead name case

Author: glessard

Sources/System/MachPort.swift

@@ -83,7 +83,11 @@ public enum Mach {
     deinit {
       if _name == 0xFFFFFFFF /* MACH_PORT_DEAD */ {
         precondition(RightType.self != ReceiveRight.self, "Receive rights cannot be dead names")
-        _machPrecondition(mach_port_mod_refs(mach_task_self_, _name, MACH_PORT_RIGHT_DEAD_NAME, -1))
+        if RightType.self == SendRight.self {
+          _machPrecondition(mach_port_mod_refs(mach_task_self_, _name, MACH_PORT_RIGHT_SEND, -1))
+        } else if RightType.self == SendOnceRight.self {
+          _machPrecondition(mach_port_mod_refs(mach_task_self_, _name, MACH_PORT_RIGHT_SEND_ONCE, -1))
+        }
       } else {
         if RightType.self == ReceiveRight.self {
           _machPrecondition(mach_port_destruct(mach_task_self_, _name, 0, _context))
@@ -135,6 +139,7 @@ extension Mach.Port where RightType == Mach.ReceiveRight {
   /// The underlying port right will be automatically deallocated when
   /// the Mach.Port object is destroyed.
   public init(name: mach_port_name_t, context: mach_port_context_t) {
+    precondition(name != mach_port_name_t(MACH_PORT_NULL), "Mach.Port cannot be initialized with MACH_PORT_NULL")
     self._name = name
     self._context = context
   }

Tests/SystemTests/MachPortTests.swift

@@ -210,6 +210,20 @@ final class MachPortTests: XCTestCase {
             XCTAssertEqual(context, $1)
         }
     }
+
+    func testDeinitDeadSendRight() throws {
+        let send = Mach.Port<Mach.SendRight>(name: 0xffffffff)
+        send.withBorrowedName {
+            XCTAssertEqual($0, .max)
+        }
+        _ = consume send
+
+        let send1 = Mach.Port<Mach.SendOnceRight>(name: 0xffffffff)
+        send1.withBorrowedName {
+            XCTAssertEqual($0, .max)
+        }
+        _ = consume send1
+    }
 }
 
 #endif