((...)) fix

[Zoltan Hidvegi <hzoli@cs.elte.hu>]

There are two problems with the rewritten ((...)): it dumps core on (())
and it substitutes its body twice.

Zoltan

*** exec.c	1996/11/17 01:57:26	3.1.0.2
--- exec.c	1996/11/23 23:34:17	3.1.0.3
***************
*** 2356,2370 ****
  int
  execarith(Cmd cmd)
  {
!     char *e = (char *) getdata(firstnode(cmd->args));
!     int val;
  
!     singsub(&e);
!     if (errflag)
! 	return 1;
!     val = matheval(e);
      errflag = 0;
!     return(!val);
  }
  
  /* perform time ... command */
--- 2356,2368 ----
  int
  execarith(Cmd cmd)
  {
!     char *e;
!     long val = 0;
  
!     while ((e = (char *) ugetnode(cmd->args)))
! 	val = matheval(e);
      errflag = 0;
!     return !val;
  }
  
  /* perform time ... command */