From 6a9266898eef59a458680a59b427755b58ca3c55 Mon Sep 17 00:00:00 2001
From: "Steffen (Daode) Nurpmeso" <steffen@sdaoden.eu>
Date: Fri, 12 Aug 2016 14:44:38 +0200
Subject: [PATCH] Add n_signal(), our future (v15) sigaction(2) call-in

---
 nail.h     |  7 ++++---
 nailfuns.h |  5 ++++-
 signal.c   | 13 +++++++++++++
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/nail.h b/nail.h
index 8e8ac32e..d46f4250 100644
--- a/nail.h
+++ b/nail.h
@@ -522,7 +522,7 @@ do {\
 #define V_(S)           S
 
 /*
- * Types
+ * Types TODO v15: n_XX_t
  */
 
 #ifdef UINT8_MAX
@@ -718,7 +718,7 @@ typedef char            wc_t; /* Yep: really 8-bit char */
 enum {FAL0, TRU1, TRUM1 = -1};
 typedef si8_t           bool_t;
 
-/* Add shorter aliases for "normal" integers */
+/* Add shorter aliases for "normal" integers TODO v15 -> n_XX_t */
 typedef unsigned long   ul_i;
 typedef unsigned int    ui_i;
 typedef unsigned short  us_i;
@@ -729,7 +729,8 @@ typedef signed int      si_i;
 typedef signed short    ss_i;
 typedef signed char     sc_i;
 
-typedef void (          *sighandler_type)(int);
+typedef void (          *sighandler_type)(int); /* TODO v15 obsolete */
+typedef void (          *n_sighdl_t)(int);
 
 enum authtype {
    AUTHTYPE_NONE     = 1<<0,
diff --git a/nailfuns.h b/nailfuns.h
index 36f7f358..8d95dc0d 100644
--- a/nailfuns.h
+++ b/nailfuns.h
@@ -1717,9 +1717,12 @@ FL char *      n_shell_quote_cp(char const *cp, bool_t rndtrip);
 
 FL void        n_raise(int signo);
 
-/* Provide BSD-like signal() on all (POSIX) systems */
+/* Provide BSD-like signal() on all systems TODO v15 -> SysV -> n_signal() */
 FL sighandler_type safe_signal(int signum, sighandler_type handler);
 
+/* Provide reproducable non-restartable signal handler installation */
+FL n_sighdl_t  n_signal(int signo, n_sighdl_t hdl);
+
 /* Hold *all* signals but SIGCHLD, and release that total block again */
 FL void        hold_all_sigs(void);
 FL void        rele_all_sigs(void);
diff --git a/signal.c b/signal.c
index b36ab712..52fa02ac 100644
--- a/signal.c
+++ b/signal.c
@@ -154,6 +154,19 @@ safe_signal(int signum, sighandler_type handler)
    return rv;
 }
 
+FL n_sighdl_t
+n_signal(int signo, n_sighdl_t hdl){
+   struct sigaction nact, oact;
+   NYD2_ENTER;
+
+   nact.sa_handler = hdl;
+   sigemptyset(&nact.sa_mask);
+   nact.sa_flags = 0;
+   hdl = (sigaction(signo, &nact, &oact) != 0) ? SIG_ERR : oact.sa_handler;
+   NYD2_LEAVE;
+   return hdl;
+}
+
 FL void
 hold_all_sigs(void)
 {
-- 
2.11.4.GIT