Re: prob: fg not sending CONT to 'make' children

["Bart Schaefer" <schaefer@xxxxxxxxxxxxxxxxxxxxxxx>]

On Aug 29,  3:35am, Will Day wrote:
} Subject: prob: fg not sending CONT to 'make' children
}
} I ran into the following problem under 3.1.6 while doing a recompile; after
} stopping (ctrl-Z) the make process, doing an 'fg' would not continue the
} make process.  Looking at the process tree, the make itself is continued,
} but its child process is still stopped.

There seems to be something wrong in signals.c:killjb().

} Another datapoint is that I generally use a shell function to run make; if
} I _don't_ use the function, it works properly.

I'm able to reproduce this in both 3.0.6 and 3.1.6-pws-1 on my linux box,
using exactly this function:

} 	% gm() {gmake $*}

I was able to continue the make by running `ps' to get the gmake process
ID (in my case it was 2888) and then running

    kill -CONT -2888 && fg

Note the negated PID, which turns the kill() into a killpg().  So gmake is
a process group leader, though whether it did that itself or zsh did it,
I'm not entirely sure; but I tend to "blame" zsh because 3.0.5 and 3.1.5
do not have the same problem.

I think this must be a case where process group management was updated
elsewhere but the change was not reflected in killjb().  The following
patch resumes the make properly in this particular example, but I'm not
sure it isn't an over-use of killpg() -- Sven, can you comment?

Index: Src/signals.c
===================================================================
@@ -591,7 +591,7 @@
         if (jn->stat & STAT_SUPERJOB) {
             if (sig == SIGCONT) {
                 for (pn = jobtab[jn->other].procs; pn; pn = pn->next)
-                    kill(pn->pid, sig);
+                    killpg(pn->pid, sig);
  
                 for (pn = jn->procs; pn->next; pn = pn->next)
                     err = kill(pn->pid, sig);

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com