From d995779208e8e3a6e308277c2d08bd4d24b90597 Mon Sep 17 00:00:00 2001
From: Matt Witherspoon <32485495+spoonincode@users.noreply.github.com>
Date: Fri, 22 Feb 2019 14:27:03 -0500
Subject: [PATCH] appbase: Block (queue) exit signals during shutdown
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When a shutdown signal is handled the sig_set is 1) canceled and 2) destroyed. This means that signals are no longer handled by boost::asio and revert back to default behavior. If someone accidentally hits ctrl-c a second time during a long shutdown they run the risk of leaving the database dirty as that second ctrl-c will be insta-kill.

This patch changes the behavior and keeps the sig_set active forever. This means that even after the first handled async_wait() on the sig_set (that starts an appbase quit), additional signals in the set are effectively “blocked” (not posix blocked, but blocked in the sense they are consumed and queued by the sig_set that is not being async_wait()ed on)
---
 libraries/appbase | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/appbase b/libraries/appbase
index 2208d40578f..b2f134a27f5 160000
--- a/libraries/appbase
+++ b/libraries/appbase
@@ -1 +1 @@
-Subproject commit 2208d40578fb206978418c1df2bb8408ecef3fe7
+Subproject commit b2f134a27f5022805985faf88400458ef6f0ae3c