From 570dcb63092c73e4f14236ded401698c6663416d Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Mon, 28 Dec 2015 07:00:01 +0100
Subject: [PATCH] command/Error: support nested exceptions

---
 src/command/CommandError.cxx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/command/CommandError.cxx b/src/command/CommandError.cxx
index 941a7c990..42e622727 100644
--- a/src/command/CommandError.cxx
+++ b/src/command/CommandError.cxx
@@ -171,7 +171,12 @@ ToAck(std::exception_ptr ep)
 	} catch (const std::system_error &e) {
 		return ACK_ERROR_SYSTEM;
 	} catch (...) {
-		return ACK_ERROR_UNKNOWN;
+		try {
+			std::rethrow_if_nested(ep);
+			return ACK_ERROR_UNKNOWN;
+		} catch (...) {
+			return ToAck(std::current_exception());
+		}
 	}
 }