From 52cd509b57cb3d4bb4091729b5baa7a639495a26 Mon Sep 17 00:00:00 2001
From: Davin McCall <davmac@davmac.org>
Date: Fri, 3 May 2019 20:00:02 +1000
Subject: [PATCH] Slight re-work of Musl utmp support detection.

---
 src/includes/dinit-utmp.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/includes/dinit-utmp.h b/src/includes/dinit-utmp.h
index 4499876..f02eca2 100644
--- a/src/includes/dinit-utmp.h
+++ b/src/includes/dinit-utmp.h
@@ -12,6 +12,11 @@
 #ifndef USE_UTMPX
 #if __linux__ || __FreeBSD__ || __DragonFly__
 #define USE_UTMPX 1
+#if __linux__
+// Should be safe to #include <utmpx.h>, but it may be stub implementation (Musl). Need to check
+// that after include:
+#define CHECK_UTMP_PATH 1
+#endif
 #else
 #define USE_UTMPX 0
 #endif
@@ -37,11 +42,14 @@
 #include <utmpx.h>
 // Musl has a utmpx.h header but only stub implementations of the functions, and does not define _PATH_UTMPX
 // nor _PATH_WTMPX.
+#if CHECK_UTMP_PATH
+#undef CHECK_UTMP_PATH
 #if !defined(_PATH_UTMPX) || !defined(_PATH_WTMPX)
 #undef USE_UTMPX
 #define USE_UTMPX 0
 #endif
 #endif
+#endif
 
 #if USE_UTMPX
 
-- 
2.25.1