sfeed_curses

commit 27d1130c82989d2773c5b4b3957c66ae0ed20706
parent 951c9714bff19a8919af72d2e0e837b2a6521ce5
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Mon, 29 Jun 2020 19:46:39 +0200

use sigaction instead of signal and enforce BSD signal semantics (SA_RESTART)

Noticed while testing on Void Linux (glibc) and compiling without _BSD_SOURCE.
SIGWINCH is an extension but it will compile.
It will (silently) use different Linux semantics and cause issues on SIGWINCH.

So use sigaction and make sure to set SA_RESTART.

Diffstat:
M
sfeed_curses.c
 | 
16
++++++++++++++--

1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/sfeed_curses.c b/sfeed_curses.c
@@ -353,6 +353,8 @@ mousemode(int on)
 void
 cleanup(void)
 {
+	struct sigaction sa;
+
 	if (!needcleanup)
 		return;
 
@@ -369,7 +371,11 @@ cleanup(void)
 	resettitle();
 	fflush(stdout);
 
-	signal(SIGWINCH, SIG_DFL);
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART;
+	sa.sa_handler = SIG_DFL;
+	if (sigaction(SIGWINCH, &sa, NULL) == -1)
+		err(1, "sigaction: SIGWINCH");
 
 	needcleanup = 0;
 }
@@ -396,6 +402,8 @@ getwinsize(void)
 void
 init(void)
 {
+	struct sigaction sa;
+
 	tcgetattr(ttyfd, &tsave);
 	memcpy(&tcur, &tsave, sizeof(tcur));
 	tcur.c_lflag &= ~(ECHO|ICANON);
@@ -415,7 +423,11 @@ init(void)
 
 	fflush(stdout);
 
-	signal(SIGWINCH, sighandler);
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART; /* require BSD signal semantics */
+	sa.sa_handler = sighandler;
+	if (sigaction(SIGWINCH, &sa, NULL) == -1)
+		err(1, "sigaction: SIGWINCH");
 
 	needcleanup = 1;
 }