configure.ac: Use curly braces for variable

diff --git a/expat/configure.ac b/expat/configure.ac
index 8d82b899460f2279bdbef9ecf5d409bad01b0e55..fe3dc29cb69a384bd2b1dfe054c940ff9ea78e07 100644 (file)
--- a/expat/configure.ac
+++ b/expat/configure.ac
@@ -133,11 +133,11 @@ AM_CONDITIONAL([WITH_TESTS], [test x${with_tests} = xyes])
 
 
 AS_VAR_SET([EXPATCFG_ON_MINGW],[no])
-AS_CASE("$host_os",
+AS_CASE("${host_os}",
   [mingw*],
   [AS_VAR_SET([EXPATCFG_ON_MINGW],[yes])
    AC_MSG_NOTICE([detected OS: MinGW])])
-AM_CONDITIONAL([MINGW], [test x$EXPATCFG_ON_MINGW = xyes])
+AM_CONDITIONAL([MINGW], [test x${EXPATCFG_ON_MINGW} = xyes])
 
 AM_CONDITIONAL([UNICODE], [echo -- "${CPPFLAGS}${CFLAGS}" | ${FGREP} XML_UNICODE >/dev/null])