Add check for libcunit and only build the test suite if libcunit is available

Makefile.am

@@ -163,6 +163,10 @@ bin_iscsi_test_SOURCES = test-tool/iscsi-test.c \
 	test-tool/1144_persistent_reserve_access_check_eaar.c \
 	test-tool/1145_persistent_reserve_access_check_wear.c
 
+endif
+
+
+if ISCSITEST
 # libiscsi test tool using cunit
 
 noinst_PROGRAMS += bin/iscsi-test-cu

configure.ac

@@ -81,5 +81,35 @@ else
 fi
 AM_CONDITIONAL(PROGRAMS, [test "$ac_cv_have_popt" = yes])
 
+AC_MSG_CHECKING(whether libcunit is available)
+ac_save_CFLAGS="$CFLAGS"
+ac_save_LIBS="$LIBS"
+CFLAGS="$CFLAGS $GLIB_CFLAGS"
+LIBS="$GLIB_LIBS $LIBS -lcunit"
+AC_TRY_RUN([
+/*
+ * Just see if we can compile/link with libcunit
+ */
+#include <CUnit/CUnit.h>
+
+int main(int argc, const char *argv[])
+{
+	return 0;
+}
+], ac_cv_have_cunit=yes, ac_cv_have_cunit=no,
+   [echo $ac_n "compile with CUNIT. Assuming OK... $ac_c"
+    ac_cv_have_cunit=yes])
+CFLAGS="$ac_save_CFLAGS"
+LIBS="$ac_save_LIBS"
+if test "$ac_cv_have_cunit" = yes ; then
+  AC_MSG_RESULT(yes)
+else
+  AC_MSG_RESULT(no)
+  AC_MSG_NOTICE(You need libcunit to build the test suite.)
+  AC_MSG_NOTICE(The scsi/iscsi test suite will not be built.)
+fi
+AM_CONDITIONAL(ISCSITEST, [test "$ac_cv_have_cunit" = yes])
+
+
 AC_CONFIG_FILES(Makefile)
 AC_OUTPUT