Remove no-longer-needed Solaris 2.4 vfork bug workaround.

The workaround was for improving performance on Solaris 2.4, but
is getting in the way now.  Emacs will still work if someone is
still running Solaris 2.4 in a museum somewhere; Sun dropped
support for Solaris 2.4 in 2003.
* configure.ac (ac_cv_func_vfork_works): Default to 'no' on
Solaris 2.4, so that AC_FUNC_VFORK doesn't think vfork works.
* src/callproc.c (Fcall_process) [HAVE_WORKING_VFORK]:
* src/process.c (create_process) [HAVE_WORKING_VFORK]:
Omit now-unnecessary workaround for the Solaris 2.4 vfork bug,
since Emacs no longer uses vfork on that platform.

1 files changed, 8 insertions, 31 deletions

diff --git a/src/process.c b/src/process.c
index a371dece250..c654369627d 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1609,14 +1609,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 #if !defined (WINDOWSNT) && defined (FD_CLOEXEC)
   int wait_child_setup[2];
 #endif
+#ifdef SIGCHLD
   sigset_t blocked, procmask;
-  struct sigaction sigint_action;
-  struct sigaction sigquit_action;
-  struct sigaction sigpipe_action;
-#ifdef AIX
-  struct sigaction sighup_action;
 #endif
-  /* Use volatile to protect variables from being clobbered by longjmp.  */
+  /* Use volatile to protect variables from being clobbered by vfork.  */
   volatile int forkin, forkout;
   volatile int pty_flag = 0;
 
@@ -1708,25 +1704,13 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
   XPROCESS (process)->pty_flag = pty_flag;
   pset_status (XPROCESS (process), Qrun);
 
+#ifdef SIGCHLD
   /* Delay interrupts until we have a chance to store
      the new fork's pid in its process structure */
   sigemptyset (&blocked);
-#ifdef SIGCHLD
   sigaddset (&blocked, SIGCHLD);
-#endif
-#ifdef HAVE_WORKING_VFORK
-  /* On many hosts (e.g. Solaris 2.4), if a vforked child calls `signal',
-     this sets the parent's signal handlers as well as the child's.
-     So delay all interrupts whose handlers the child might munge,
-     and record the current handlers so they can be restored later.  */
-  sigaddset (&blocked, SIGINT );  sigaction (SIGINT , 0, &sigint_action );
-  sigaddset (&blocked, SIGQUIT);  sigaction (SIGQUIT, 0, &sigquit_action);
-  sigaddset (&blocked, SIGPIPE);  sigaction (SIGPIPE, 0, &sigpipe_action);
-#ifdef AIX
-  sigaddset (&blocked, SIGHUP );  sigaction (SIGHUP , 0, &sighup_action );
-#endif
-#endif /* HAVE_WORKING_VFORK */
   pthread_sigmask (SIG_BLOCK, &blocked, &procmask);
+#endif
 
   FD_SET (inchannel, &input_wait_mask);
   FD_SET (inchannel, &non_keyboard_wait_mask);
@@ -1879,8 +1863,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 	   in the child.  */
 	signal (SIGPIPE, SIG_DFL);
 
+#ifdef SIGCHLD
 	/* Stop blocking signals in the child.  */
 	pthread_sigmask (SIG_SETMASK, &procmask, 0);
+#endif
 
 	if (pty_flag)
 	  child_setup_tty (xforkout);
@@ -1959,19 +1945,10 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 #endif
     }
 
-  /* Restore the signal state whether vfork succeeded or not.
-     (We will signal an error, below, if it failed.)  */
-#ifdef HAVE_WORKING_VFORK
-  /* Restore the parent's signal handlers.  */
-  sigaction (SIGINT, &sigint_action, 0);
-  sigaction (SIGQUIT, &sigquit_action, 0);
-  sigaction (SIGPIPE, &sigpipe_action, 0);
-#ifdef AIX
-  sigaction (SIGHUP, &sighup_action, 0);
-#endif
-#endif /* HAVE_WORKING_VFORK */
+#ifdef SIGCHLD
   /* Stop blocking signals in the parent.  */
   pthread_sigmask (SIG_SETMASK, &procmask, 0);
+#endif
 
   /* Now generate the error if vfork failed.  */
   if (pid < 0)