>From 09808040ef70f62f0ffefae3a95e0d0fc7ef09a5 Mon Sep 17 00:00:00 2001
From: Michael Tokarev <address@hidden>
Date: Sat, 27 Oct 2012 16:03:34 +0400
Subject: [PATCH] disallow -daemonize with curses display or -nographic

Curses display requires stdin/out to stay on the terminal,
so -daemonize makes no sense in this case.  Instead of
leaving display uninitialized like is done since 995ee2bf469de6bb,
explicitly detect this case earlier and error out.

-nographic can actually be used with -daemonize, by redirecting
everything to a null device, but the problem is that according
to documentation and historical behavour, -nographic redirects
guest ports to stdin/out, which, again, makes no sense in case
of -daemonize.  Since -nographic is a legacy option, don't bother
fixing this case (to allow -nographic and -daemonize by redirecting
guest ports to null instead of stdin/out in this case), but disallow
it completely instead, to stop garbling host terminal.

If no display display needed and user wants to use -nographic,
the right way to go is to use
  -serial null -parallel null -monitor none -display none -vga none
instead of -nographic.

Signed-off-by: Michael Tokarev <address@hidden>
---
 vl.c |   24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/vl.c b/vl.c
index 9f99ef4..db48d62 100644
--- a/vl.c
+++ b/vl.c
@@ -3413,6 +3413,26 @@ int main(int argc, char **argv, char **envp)
         default_sdcard = 0;
     }
 
+    if (is_daemonized()) {
+        /* According to documentation and historically, -nographic redirects
+         * serial port, parallel port and monitor to stdio, which does not work
+         * with -daemonize.  We can redirect these to null instead, but since
+         * -nographic is legacy, let's just error out.
+         */
+        if (display_type == DT_NOGRAPHIC
+            /* && (default_parallel || default_serial
+                || default_monitor || default_virtcon) */) {
+            fprintf(stderr, "-nographic can not be used with -daemonize\n");
+            exit(1);
+        }
+#ifdef CONFIG_CURSES
+        if (display_type == DT_CURSES) {
+            fprintf(stderr, "curses display can not be used with -daemonize\n");
+            exit(1);
+        }
+#endif
+    }
+
     if (display_type == DT_NOGRAPHIC) {
         if (default_parallel)
             add_device_config(DEV_PARALLEL, "null");
@@ -3687,9 +3707,7 @@ int main(int argc, char **argv, char **envp)
         break;
 #if defined(CONFIG_CURSES)
     case DT_CURSES:
-        if (!is_daemonized()) {
-            curses_display_init(ds, full_screen);
-        }
+        curses_display_init(ds, full_screen);
         break;
 #endif
 #if defined(CONFIG_SDL)
-- 
1.7.10.4