[vala] posix.vapi: signal is allowed to be null (restoring the original handler)

[Jürg Billeter <juergbi src gnome org>]

commit d361a64bbe61e53b27fec118a4162c5c5259da41
Author: Michael 'Mickey' Lauer <mickey vanille-media de>
Date:   Tue Mar 10 16:53:01 2009 +0100

    posix.vapi: signal is allowed to be null (restoring the original handler)
    
    Signed-off-by: Michael 'Mickey' Lauer <mlauer vanille-media de>
---
 vapi/posix.vapi |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/vapi/posix.vapi b/vapi/posix.vapi
index 62f9211..d9633a2 100644
--- a/vapi/posix.vapi
+++ b/vapi/posix.vapi
@@ -366,7 +366,7 @@ namespace Posix {
 	public static delegate void sighandler_t (int signal);
 
 	[CCode (cheader_filename = "signal.h")]
-	public sighandler_t signal (int signum, sighandler_t handler);
+	public sighandler_t signal (int signum, sighandler_t? handler);
 
 	[CCode (cheader_filename = "string.h")]
 	public int memcmp (void* s1, void* s2, size_t n);