From 18f40cd879d9c8ac518bcfa5e39dc4f23b207d1c Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Sat, 12 Jan 2019 21:21:32 +0100
Subject: [PATCH] autoconf: fix enable flags

---
 configure.ac | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index b117a10..c995099 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,17 +69,30 @@ AM_CONDITIONAL(OS_LINUX, test "x$os" = xlinux)
 AM_CONDITIONAL(OS_DARWIN, test "x$os" = xdarwin)
 
 # Examples build
-AC_ARG_ENABLE([disable-examples-build], [AS_HELP_STRING([--disable-examples-build],
-	[disable building example applications [default=no]])],
-	[disable_build_examples=$enableval],
-	[disable_build_examples=no])
-AM_CONDITIONAL(BUILD_EXAMPLES, test "x$disable_build_examples" != xyes)
+AC_ARG_ENABLE([examples],
+AS_HELP_STRING([--enable-examples],
+	[enable building example applications, default: yes]),
+	[case "${enableval}" in
+		yes) build_examples=true ;;
+		no)  build_examples=false ;;
+		*)   AC_MSG_ERROR([bad value ${enableval} for --enable-examples]) ;;
+	esac],
+	[build_examples=true]
+)
+AM_CONDITIONAL(BUILD_EXAMPLES, test x"$build_examples" == x"true")
+
 # Debug enable
-AC_ARG_ENABLE([debug], [AS_HELP_STRING([--debug],
-	[turn on debugging [default=no]])],
-	[debug=$enableval],
-	[debug=no])
-AM_CONDITIONAL(DEBUG, test "x$debug" != xno)
+AC_ARG_ENABLE(debug,
+AS_HELP_STRING([--enable-debug],
+	[enable debugging, default: no]),
+	[case "${enableval}" in
+		yes) debug=true ;;
+		no)  debug=false ;;
+		*)   AC_MSG_ERROR([bad value ${enableval} for --enable-debug]) ;;
+	esac],
+	[debug=false]
+)
+AM_CONDITIONAL(DEBUG, test x"$debug" = x"true")
 
 AC_SUBST(LTLDFLAGS)