Index: eval_intern.h
===================================================================
--- eval_intern.h	(revision 29738)
+++ eval_intern.h	(working copy)
@@ -210,7 +210,6 @@
 void rb_thread_terminate_all(void);
 VALUE rb_vm_top_self();
 VALUE rb_vm_cbase(void);
-void rb_trap_restore_mask(void);
 
 #ifndef CharNext		/* defined as CharNext[AW] on Windows. */
 #define CharNext(p) ((p) + mblen(p, RUBY_MBCHAR_MAXSIZE))
Index: vm_eval.c
===================================================================
--- vm_eval.c	(revision 29738)
+++ vm_eval.c	(working copy)
@@ -1439,7 +1439,6 @@
 	VALUE desc = rb_inspect(tag);
 	rb_raise(rb_eArgError, "uncaught throw %s", RSTRING_PTR(desc));
     }
-    rb_trap_restore_mask();
     th->errinfo = NEW_THROW_OBJECT(tag, 0, TAG_THROW);
 
     JUMP_TAG(TAG_THROW);
Index: eval.c
===================================================================
--- eval.c	(revision 29738)
+++ eval.c	(working copy)
@@ -438,8 +438,6 @@
 	JUMP_TAG(TAG_FATAL);
     }
 
-    rb_trap_restore_mask();
-
     if (tag != TAG_FATAL) {
 	EXEC_EVENT_HOOK(th, RUBY_EVENT_RAISE, th->cfp->self, 0, 0);
     }
Index: signal.c
===================================================================
--- signal.c	(revision 29738)
+++ signal.c	(working copy)
@@ -538,14 +538,6 @@
     return signal_buff.size;
 }
 
-#if USE_TRAP_MASK
-# ifdef HAVE_SIGPROCMASK
-static sigset_t trap_last_mask;
-# else
-static int trap_last_mask;
-# endif
-#endif
-
 #if HAVE_PTHREAD_H
 #include <pthread.h>
 #endif
@@ -880,13 +872,6 @@
     vm->trap_list[sig].cmd = command;
     vm->trap_list[sig].safe = rb_safe_level();
     /* enable at least specified signal. */
-#if USE_TRAP_MASK
-#ifdef HAVE_SIGPROCMASK
-    sigdelset(&arg->mask, sig);
-#else
-    arg->mask &= ~sigmask(sig);
-#endif
-#endif
     return oldcmd;
 }
 
@@ -896,19 +881,10 @@
 {
     /* enable interrupt */
     pthread_sigmask(SIG_SETMASK, &arg->mask, NULL);
-    trap_last_mask = arg->mask;
     return 0;
 }
 #endif
 
-void
-rb_trap_restore_mask(void)
-{
-#if USE_TRAP_MASK
-    pthread_sigmask(SIG_SETMASK, &trap_last_mask, NULL);
-#endif
-}
-
 /*
  * call-seq:
  *   Signal.trap( signal, command ) -> obj
@@ -1031,12 +1007,6 @@
     } else {
 	GET_VM()->trap_list[sig].cmd = 0;
     }
-
-#if USE_TRAP_MASK
-    sigdelset(&mask, sig);
-    pthread_sigmask(SIG_SETMASK, &mask, NULL);
-    trap_last_mask = mask;
-#endif
 }
 #endif