Fix Process.detach thread behavior

kernel/common/process.rb

@@ -376,27 +376,6 @@ class << self
     alias_method :waitpid2, :wait2
   end
 
-  #
-  # Indicate disinterest in child process.
-  #
-  # Sets up an internal wait on the given process ID.
-  # Only possibly real pids, i.e. positive numbers,
-  # may be waited for.
-  #
-  # TODO: Should an error be raised on ECHILD? --rue
-  #
-  # TODO: This operates on the assumption that waiting on
-  #       the event consumes very little resources. If this
-  #       is not the case, the check should be made WNOHANG
-  #       and called periodically.
-  #
-  def self.detach(pid)
-    raise ArgumentError, "Only positive pids may be detached" unless pid > 0
-
-    # The evented system does not need a loop
-    Thread.new { Process.wait pid }
-  end
-
   #--
   # TODO: Most of the fields aren't implemented yet.
   # TODO: Also, these objects should only need to be constructed by

kernel/common/process18.rb

@@ -25,6 +25,20 @@ def self.exec(cmd, *args)
       Process.perform_exec prog, argv
     end
   end
+
+  # TODO: Should an error be raised on ECHILD? --rue
+  #
+  # TODO: This operates on the assumption that waiting on
+  #       the event consumes very little resources. If this
+  #       is not the case, the check should be made WNOHANG
+  #       and called periodically.
+  #
+  def self.detach(pid)
+    raise ArgumentError, "Only positive pids may be detached" unless pid > 0
+
+    # The evented system does not need a loop
+    Thread.new { Process.wait pid; $? }
+  end
 end
 
 module Kernel

kernel/common/process19.rb

@@ -289,6 +289,23 @@ def self.spawn(*args)
       pid
     end
   end
+
+  # TODO: Should an error be raised on ECHILD? --rue
+  #
+  # TODO: This operates on the assumption that waiting on
+  #       the event consumes very little resources. If this
+  #       is not the case, the check should be made WNOHANG
+  #       and called periodically.
+  #
+  def self.detach(pid)
+    raise ArgumentError, "Only positive pids may be detached" unless pid > 0
+
+    thread = Thread.new { Process.wait pid; $? }
+    thread[:pid] = pid
+    def thread.pid; self[:pid] end
+
+    thread
+  end
 end
 
 module Kernel