From 01a75c04b1912856d60629250b80873199449811 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 5 Feb 2020 22:31:22 +0100
Subject: [PATCH] Fix rt-safety (const reference, not const copy)

PluginInsert (and a few other places) iterate over channel
mappings using a const iterator. However mappings()
allocated memory since it was copied
---
 libs/ardour/ardour/chan_mapping.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libs/ardour/ardour/chan_mapping.h b/libs/ardour/ardour/chan_mapping.h
index 64ffc32890..07b623f8e1 100644
--- a/libs/ardour/ardour/chan_mapping.h
+++ b/libs/ardour/ardour/chan_mapping.h
@@ -106,8 +106,8 @@ public:
 	typedef std::map<uint32_t, uint32_t>    TypeMapping;
 	typedef std::map<DataType, TypeMapping> Mappings;
 
-	Mappings       mappings()       { return _mappings; }
-	const Mappings mappings() const { return _mappings; }
+	Mappings        mappings()       { return _mappings; }
+	const Mappings& mappings() const { return _mappings; }
 
 	bool operator==(const ChanMapping& other) const {
 		return (_mappings == other._mappings);