* process.c: Make sure we don't miss processes exiting, by having

	the sigchld handler clear *input_available_clear_time.
	(wait_reading_process_input): Check for process activity after
	setting the timeout and calling set_waiting_for_input.
	(sigchld_handler): If the process which has exited is one we care
	about, clear *input_available_clear_time.

	* process.c (process_send_signal): Use TERMIOS functions in
	preference to BSD ioctls.  Some systems attempt to provide the BSD
	functions for backward compatibility, and get it wrong.

1 files changed, 65 insertions, 18 deletions

diff --git a/src/process.c b/src/process.c
index d0d90e90c0b..95be209f94c 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1717,23 +1717,6 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
       if (XINT (read_kbd) >= 0)
         QUIT;
 
-      /* If status of something has changed, and no input is available,
-         notify the user of the change right away */
-      if (update_tick != process_tick && do_display)
-        {
-          Atemp = input_wait_mask;
-          EMACS_SET_SECS_USECS (timeout, 0, 0);
-          if (select (MAXDESC, &Atemp, 0, 0, &timeout) <= 0)
-            status_notify ();
-        }
-
-      /* Don't wait for output from a non-running process.  */
-      if (wait_proc != 0 && !NILP (wait_proc->raw_status_low))
-        update_status (wait_proc);
-      if (wait_proc != 0
-          && ! EQ (wait_proc->status, Qrun))
-        break;
-
       /* Compute time from now till when time limit is up */
       /* Exit if already run out */
       if (time_limit == -1)
@@ -1757,10 +1740,33 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
         }
 
       /* Cause C-g and alarm signals to take immediate action,
-         and cause input available signals to zero out timeout */
+         and cause input available signals to zero out timeout.
+
+         It is important that we do this before checking for process
+         activity.  If we get a SIGCHLD after the explicit checks for
+         process activity, timeout is the only way we will know.  */
       if (XINT (read_kbd) < 0)
         set_waiting_for_input (&timeout);
 
+      /* If status of something has changed, and no input is
+         available, notify the user of the change right away.  After
+         this explicit check, we'll let the SIGCHLD handler zap
+         timeout to get our attention.  */
+      if (update_tick != process_tick && do_display)
+        {
+          Atemp = input_wait_mask;
+          EMACS_SET_SECS_USECS (timeout, 0, 0);
+          if (select (MAXDESC, &Atemp, 0, 0, &timeout) <= 0)
+            status_notify ();
+        }
+
+      /* Don't wait for output from a non-running process.  */
+      if (wait_proc != 0 && !NILP (wait_proc->raw_status_low))
+        update_status (wait_proc);
+      if (wait_proc != 0
+          && ! EQ (wait_proc->status, Qrun))
+        break;
+
       /* Wait till there is something to do */
 
       Available = input_wait_mask;
@@ -2326,6 +2332,35 @@ process_send_signal (process, signo, current_group, nomsg)
       /* If possible, send signals to the entire pgrp
          by sending an input character to it.  */
 
+      /* TERMIOS is the latest and bestest, and seems most likely to
+         work.  If the system has it, use it.  */
+#ifdef HAVE_TERMIOS
+      struct termios t;
+
+      switch (signo)
+        {
+        case SIGINT:
+          tcgetattr (XFASTINT (p->infd), &t);
+          send_process (proc, &t.c_cc[VINTR], 1);
+          return Qnil;
+
+        case SIGQUIT:
+          tcgetattr (XFASTINT (p->infd), &t);
+          send_process (proc, &t.c_cc[VQUIT], 1);
+          return Qnil;
+
+        case SIGTSTP:
+          tcgetattr (XFASTINT (p->infd), &t);
+#ifdef VSWTCH
+          send_process (proc, &t.c_cc[VSWTCH], 1);
+#else
+          send_process (proc, &t.c_cc[VSUSP], 1);
+#endif
+          return Qnil;
+        }
+
+#else /* ! HAVE_TERMIOS */
+
       /* On Berkeley descendants, the following IOCTL's retrieve the
          current control characters.  */
 #if defined (TIOCGLTC) && defined (TIOCGETC)
@@ -2380,6 +2415,7 @@ process_send_signal (process, signo, current_group, nomsg)
          you'd better be using one of the alternatives above!  */
 #endif /* ! defined (TCGETA) */
 #endif /* ! defined (TIOCGLTC) && defined (TIOCGETC) */
+#endif /* ! defined HAVE_TERMIOS */
 #endif /* ! defined (SIGNALS_VIA_CHARACTERS) */
 
 #ifdef TIOCGPGRP 
@@ -2631,6 +2667,7 @@ sigchld_handler (signo)
   int old_errno = errno;
   Lisp_Object proc;
   register struct Lisp_Process *p;
+  extern EMACS_TIME *input_available_clear_time;
 
 #ifdef BSD4_1
   extern int sigheld;
@@ -2713,6 +2750,11 @@ sigchld_handler (signo)
           if (WIFSIGNALED (w) || WIFEXITED (w))
             if (XFASTINT (p->infd))
               FD_CLR (XFASTINT (p->infd), &input_wait_mask);
+
+          /* Tell wait_reading_process_input that it needs to wake up and
+             look around.  */
+          if (input_available_clear_time)
+            EMACS_SET_SECS_USECS (*input_available_clear_time, 0, 0);
         }
 
         /* There was no asynchronous process found for that id.  Check
@@ -2730,6 +2772,11 @@ sigchld_handler (signo)
 #else
             synch_process_death = sys_errlist[WTERMSIG (w)];
 #endif
+
+          /* Tell wait_reading_process_input that it needs to wake up and
+             look around.  */
+          if (input_available_clear_time)
+            EMACS_SET_SECS_USECS (*input_available_clear_time, 0, 0);
         }
 
       /* On some systems, we must return right away.