ignore spurious sigchilds on sunos

src/cmd/9term/9term.c

@@ -314,9 +314,17 @@ hangupnote(void *a, char *msg)
 		noted(NDFLT);
 	}
 	if(strstr(msg, "child")){
-		/* bug: do better */
+		char buf[128];
+		int n;
+
+		n = awaitnohang(buf, sizeof buf-1);
+		if(n > 0){
+			buf[n] = 0;
+			if(atoi(buf) == rcpid)
 				threadexitsall(0);
 		}
+		noted(NCONT);
+	}
 	noted(NDFLT);
 }
 
@@ -1520,7 +1528,6 @@ backnl(uint p, uint n)
 			return p;
 		p--;
 	}
-	return 0; /* alef bug */
 }
 
 void