test copies of dead mach port names

Author: glessard

Sources/System/MachPort.swift

@@ -308,7 +308,7 @@ extension Mach.Port where RightType == Mach.SendRight {
 
     // name is the same because send rights are coalesced
     let kr = mach_port_insert_right(mach_task_self_, _name, _name, mach_msg_type_name_t(how))
-    if kr == KERN_INVALID_CAPABILITY {
+    if kr == KERN_INVALID_NAME {
       throw Mach.PortRightError.deadName
     }
     _machPrecondition(kr)

Tests/SystemTests/MachPortTests.swift

@@ -183,6 +183,17 @@ final class MachPortTests: XCTestCase {
         XCTAssertEqual(same, one)
 
     }
+
+    func testCopyDeadName() throws {
+        let send = Mach.Port<Mach.SendRight>(name: 0xffffffff)
+        do {
+            let copy = try send.copySendRight()
+            _ = copy
+        }
+        catch Mach.PortRightError.deadName {
+            _ = send.relinquish()
+        }
+    }
 }
 
 #endif