From d203c554faa00fec55377d6640c8fb335a611a09 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niklas=20Hamb=C3=BCchen?= <mail@nh2.me>
Date: Wed, 3 Jul 2019 01:46:07 +0200
Subject: [PATCH] Fix C++ compatibility with older editline versions.

For example, Ubuntu 16.04 and many similar long-term-support distros
have older versions.
---
 src/nix/repl.cc | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/nix/repl.cc b/src/nix/repl.cc
index d8f812149..f857b2e89 100644
--- a/src/nix/repl.cc
+++ b/src/nix/repl.cc
@@ -9,7 +9,14 @@
 #include <readline/history.h>
 #include <readline/readline.h>
 #else
+// editline < 1.15.2 don't wrap their API for C++ usage
+// (added in https://github.com/troglobit/editline/commit/91398ceb3427b730995357e9d120539fb9bb7461).
+// This results in linker errors due to to name-mangling of editline C symbols.
+// For compatibility with these versions, we wrap the API here
+// (wrapping multiple times on newer versions is no problem).
+extern "C" {
 #include <editline.h>
+}
 #endif
 
 #include "shared.hh"