Re: Racing condition leads to unstable exit code

[Chet Ramey]

On 5/4/17 3:05 PM, Chet Ramey wrote:

>> Would the fix be backported to stable?
> 
> Let me see if I can put together a patch for you to test.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    c...@case.edu    http://cnswww.cns.cwru.edu/~chet/

*** ../bash-4.4/lib/sh/zread.c  2014-12-22 10:48:04.000000000 -0500
--- lib/sh/zread.c      2016-09-29 15:21:36.000000000 -0400
***************
*** 38,42 ****
--- 38,45 ----
  #endif
  
+ extern int executing_builtin;
+ 
  extern void check_signals_and_traps (void);
+ extern void check_signals (void);
  extern int signal_is_trapped (int);
  
***************
*** 51,69 ****
    ssize_t r;
  
- #if 0
- #if defined (HAVE_SIGINTERRUPT)
-   if (signal_is_trapped (SIGCHLD))
-     siginterrupt (SIGCHLD, 1);
- #endif
- #endif
- 
    while ((r = read (fd, buf, len)) < 0 && errno == EINTR)
!     check_signals_and_traps ();       /* XXX - should it be check_signals()? 
*/
! 
! #if 0 
! #if defined (HAVE_SIGINTERRUPT)
!   siginterrupt (SIGCHLD, 0);
! #endif
! #endif
  
    return r;
--- 54,64 ----
    ssize_t r;
  
    while ((r = read (fd, buf, len)) < 0 && errno == EINTR)
!     /* XXX - bash-5.0 */
!     /* We check executing_builtin and run traps here for backwards 
compatibility */
!     if (executing_builtin)
!       check_signals_and_traps ();     /* XXX - should it be check_signals()? 
*/
!     else
!       check_signals ();
  
    return r;