RFA[threads]: Fork event updates, part the thirteenth

[Daniel Jacobowitz <drow@mvista.com>]

Now is where it starts to get interesting.  Michael, I mentioned this patch
to you at lunch last week.  If you take a short-lived program, run it, and
detach it, and run it again, you'll see the exit of the _previous_ copy. 
Then GDB gets hopelessly confused.  I have a testcase for this which I'll
post in a moment.

The reason it's included here is that that's essentially what happens if you
are using "set follow-fork-mode child".  We detach from the parent, which
exits, confusing GDB.

Is this OK?

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

2002-12-15  Daniel Jacobowitz  <drow@mvista.com>

	* lin-lwp.c (child_wait): Ignore exit statuses for processes other
	than inferior_ptid.
	(lin_lwp_wait): Ignore exit statuses for unknown LWPs.

Index: lin-lwp.c
===================================================================
RCS file: /cvs/src/src/gdb/lin-lwp.c,v
retrieving revision 1.39
diff -u -p -r1.39 lin-lwp.c
--- lin-lwp.c	9 Dec 2002 18:41:42 -0000	1.39
+++ lin-lwp.c	15 Dec 2002 21:16:34 -0000
@@ -964,6 +964,14 @@ child_wait (ptid_t ptid, struct target_w
 	pid = waitpid (GET_PID (ptid), &status, __WCLONE);
       save_errno = errno;
 
+      /* Make sure we don't report an event for the exit of the
+	 original program, if we've detached from it.  */
+      if (pid != -1 && ! WIFSTOPPED (status) && pid != GET_PID (inferior_ptid))
+	{
+	  pid = -1;
+	  save_errno = EINTR;
+	}
+
       clear_sigio_trap ();
       clear_sigint_trap ();
     }
@@ -1091,6 +1099,17 @@ lin_lwp_wait (ptid_t ptid, struct target
 	  gdb_assert (pid == -1 || lwpid == pid);
 
 	  lp = find_lwp_pid (pid_to_ptid (lwpid));
+
+	  /* Make sure we don't report an event for the exit of an LWP not in
+	     our list, i.e.  not part of the current process.  This can happen
+	     if we detach from a program we original forked and then it
+	     exits.  */
+	  if (! WIFSTOPPED (status) && ! lp)
+	    {
+	      status = 0;
+	      continue;
+	    }
+
 	  if (! lp)
 	    {
 	      lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));