From 4774179cb9e04030485773adf2b7b1055a10faeb Mon Sep 17 00:00:00 2001
From: Denis Vlasenko
Date: Tue, 10 Mar 2009 16:01:57 +0000
Subject: mail.c: more robust handling of SIGCHLD init: more robust signal
 handling

---
 mailutils/mail.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

(limited to 'mailutils/mail.c')

diff --git a/mailutils/mail.c b/mailutils/mail.c
index 71f46c8..68883ff 100644
--- a/mailutils/mail.c
+++ b/mailutils/mail.c
@@ -48,6 +48,12 @@ void FAST_FUNC launch_helper(const char **argv)
 	xpipe(pipes);
 	xpipe(pipes + 2);
 
+	// NB: handler must be installed before vfork
+	bb_signals(0
+		+ (1 << SIGCHLD)
+		+ (1 << SIGALRM)
+		, signal_handler);
+
 	G.helper_pid = vfork();
 	if (G.helper_pid < 0)
 		bb_perror_msg_and_die("vfork");
@@ -60,15 +66,12 @@ void FAST_FUNC launch_helper(const char **argv)
 
 	if (!G.helper_pid) {
 		// child: try to execute connection helper
+		// NB: SIGCHLD & SIGALRM revert to SIG_DFL on exec
 		BB_EXECVP(*argv, (char **)argv);
 		_exit(127);
 	}
 
 	// parent
-	bb_signals(0
-		+ (1 << SIGCHLD)
-		+ (1 << SIGALRM)
-		, signal_handler);
 	// check whether child is alive
 	//redundant:signal_handler(SIGCHLD);
 	// child seems OK -> parent goes on
-- 
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