start-stop-daemon: do not lose error messages with -b

function                                             old     new   delta
start_stop_daemon_main                              1186    1206     +20
bb_daemonize_or_rexec                                196     212     +16
bb_banner                                             47      46      -1
packed_usage                                       34656   34645     -11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/2 up/down: 36/-12)             Total: 24 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index a570ddbf2..2055c4b71 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -296,9 +296,12 @@ void FAST_FUNC bb_daemonize_or_rexec(int flags, char **argv)
         }
 
         if (flags & DAEMON_DEVNULL_STDIO) {
-                xdup2(fd, 0);
-                xdup2(fd, 1);
-                xdup2(fd, 2);
+                if (flags & DAEMON_DEVNULL_STDIN)
+                        xdup2(fd, 0);
+                if (flags & DAEMON_DEVNULL_OUTERR) {
+                        xdup2(fd, 1);
+                        xdup2(fd, 2);
+                }
         } else {
                 /* have 0,1,2 open at least to /dev/null */
                 while ((unsigned)fd < 2)