went back to non-blokcing IO

it looks like ssh is willing to accept a non-blocking fd when used as
a transport, this seems to avoid the Solaris socketpair bug

io.c

@@ -159,6 +159,11 @@ static int read_timeout(int fd, char *buf, int len)
 			continue;
 		}
 
+		if (n == -1 && 
+		    (errno == EWOULDBLOCK || errno == EAGAIN)) {
+			continue;
+		}
+
 
 		if (n == 0) {
 			if (eof_error) {
@@ -364,12 +369,17 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 		if (FD_ISSET(fd, &w_fds)) {
 			int ret, n = len-total;
 			
-			ret = write(fd,buf+total,n?n:1);
+			ret = write(fd,buf+total,n);
 
 			if (ret == -1 && errno == EINTR) {
 				continue;
 			}
 
+			if (ret == -1 && 
+			    (errno == EWOULDBLOCK || errno == EAGAIN)) {
+				continue;
+			}
+
 			if (ret <= 0) {
 				rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
 				exit_cleanup(RERR_STREAMIO);