Use pkg-config for curses, if possible

bin/varnishhist/Makefile.am

@@ -18,4 +18,4 @@ varnishhist_LDADD = \
 	$(top_builddir)/lib/libvarnishapi/libvarnishapi.la \
 	-lm \
 	@SAN_LDFLAGS@ \
-	@CURSES_LIB@ ${RT_LIBS} ${PTHREAD_LIBS}
+	@CURSES_LIBS@ ${RT_LIBS} ${PTHREAD_LIBS}

bin/varnishstat/Makefile.am

@@ -18,4 +18,4 @@ varnishstat_CFLAGS = \
 varnishstat_LDADD = \
 	$(top_builddir)/lib/libvarnishapi/libvarnishapi.la \
 	@SAN_LDFLAGS@ \
-	@CURSES_LIB@ ${RT_LIBS} ${LIBM} ${PTHREAD_LIBS}
+	@CURSES_LIBS@ ${RT_LIBS} ${LIBM} ${PTHREAD_LIBS}

bin/varnishtop/Makefile.am

@@ -17,4 +17,4 @@ varnishtop_CFLAGS = \
 varnishtop_LDADD = \
 	$(top_builddir)/lib/libvarnishapi/libvarnishapi.la \
 	@SAN_LDFLAGS@ \
-	@CURSES_LIB@ ${RT_LIBS} ${LIBM} ${PTHREAD_LIBS}
+	@CURSES_LIBS@ ${RT_LIBS} ${LIBM} ${PTHREAD_LIBS}

configure.ac

@@ -82,11 +82,6 @@ _VARNISH_CHECK_LIB(nsl, getaddrinfo)
 
 AC_SUBST(NET_LIBS, "${SOCKET_LIBS} ${NSL_LIBS}")
 
-AX_WITH_CURSES
-if test "x$ax_cv_curses" != xyes; then
-   AC_MSG_ERROR([requires an X/Open-compatible Curses library])
-fi
-
 # Userland slab allocator from Solaris, ported to other systems
 AC_CHECK_HEADERS([umem.h], [_VARNISH_CHECK_LIB(umem, umem_alloc)])
 
@@ -187,6 +182,21 @@ AC_CHECK_HEADERS([edit/readline/readline.h],
 		])
 	])
 
+PKG_CHECK_MODULES([CURSES], [ncursesw], [], [
+	PKG_CHECK_MODULES([CURSES], [ncurses], [], [
+		PKG_CHECK_MODULES([CURSES], [curses], [], [
+AX_WITH_CURSES
+if test "x$ax_cv_curses" != xyes; then
+	AC_MSG_ERROR([requires an X/Open-compatible Curses library])
+fi
+CURSES_LIBS="$CURSES_LIB"
+		])
+	])
+])
+AC_SUBST([CURSES_LIBS])
+
+AC_CHECK_HEADERS([ncursesw/curses.h ncursesw.h ncurses/curses.h ncurses.h curses.h])
+
 # Checks for header files.
 AC_HEADER_STDC
 AC_CHECK_HEADERS([sys/endian.h])