try harder to put background jobs in background; do not print in response to SIGPIPE
diff --git a/src/cmd/rc/exec.c b/src/cmd/rc/exec.c
index fc7b630..e6cde9e 100644
--- a/src/cmd/rc/exec.c
+++ b/src/cmd/rc/exec.c
@@ -1,3 +1,6 @@
+#include <u.h>
+#include <signal.h>
+#include <sys/ioctl.h>
#include "rc.h"
#include "getflags.h"
#include "exec.h"
@@ -220,6 +223,7 @@
}
void Xasync(void){
int null=open("/dev/null", 0);
+ int tty;
int pid;
char npid[10];
if(null<0){
@@ -232,7 +236,33 @@
Xerror("try again");
break;
case 0:
- pushredir(ROPEN, null, 0);
+ /*
+ * I don't know what the right thing to do here is,
+ * so this is all experimentally determined.
+ * If we just dup /dev/null onto 0, then running
+ * ssh foo & will reopen /dev/tty, try to read a password,
+ * get a signal, and repeat, in a tight loop, forever.
+ * Arguably this is a bug in ssh (it behaves the same
+ * way under bash as under rc) but I'm fixing it here
+ * anyway. If we dissociate the process from the tty,
+ * then it won't be able to open /dev/tty ever again.
+ * The SIG_IGN on SIGTTOU makes writing the tty
+ * (via fd 1 or 2, for example) succeed even though
+ * our pgrp is not the terminal's controlling pgrp.
+ */
+ if((tty=open("/dev/tty", OREAD)) >= 0){
+ /*
+ * Should make reads of tty fail, writes succeed.
+ */
+ signal(SIGTTIN, SIG_IGN);
+ signal(SIGTTOU, SIG_IGN);
+ ioctl(tty, TIOCNOTTY);
+ close(tty);
+ }
+ if(isatty(0))
+ pushredir(ROPEN, null, 0);
+ else
+ close(null);
start(runq->code, runq->pc+1, runq->local);
runq->ret=0;
break;
