openvz: Add simple testcase for config file parsing function

This testcase passes before the regression is added in f0443765, fails
after that commit and passes again after the regression was fixed.

tests/openvzutilstest.c

@@ -0,0 +1,91 @@
+#include <config.h>
+
+#ifdef WITH_OPENVZ
+
+# include <stdio.h>
+# include <string.h>
+# include <unistd.h>
+
+# include "internal.h"
+# include "memory.h"
+# include "testutils.h"
+# include "util.h"
+# include "openvz/openvz_conf.h"
+
+struct testConfigParam {
+    const char *param;
+    const char *value;
+    int ret;
+};
+
+static struct testConfigParam configParams[] = {
+    { "OSTEMPLATE", "rhel-5-lystor", 1 },
+    { "IP_ADDRESS", "194.44.18.88", 1 },
+    { "THIS_PARAM_IS_MISSING", NULL, 0 },
+};
+
+static int
+testReadConfigParam(const void *data ATTRIBUTE_UNUSED)
+{
+    int result = -1;
+    int i;
+    char *conf = NULL;
+    char *value = NULL;
+
+    if (virAsprintf(&conf, "%s/openvzutilstest.conf", abs_srcdir) < 0) {
+        return -1;
+    }
+
+    for (i = 0; i < ARRAY_CARDINALITY(configParams); ++i) {
+        if (openvzReadConfigParam(conf, configParams[i].param,
+                                  &value) != configParams[i].ret) {
+            goto cleanup;
+        }
+
+        if (configParams[i].ret != 1) {
+            continue;
+        }
+
+        if (STRNEQ(configParams[i].value, value)) {
+            virtTestDifference(stderr, configParams[i].value, value);
+            goto cleanup;
+        }
+    }
+
+    result = 0;
+
+cleanup:
+    VIR_FREE(conf);
+    VIR_FREE(value);
+
+    return result;
+}
+
+static int
+mymain(void)
+{
+    int result = 0;
+
+# define DO_TEST(_name)                                                       \
+        do {                                                                  \
+            if (virtTestRun("OpenVZ "#_name, 1, test##_name,                  \
+                            NULL) < 0) {                                      \
+                result = -1;                                                  \
+            }                                                                 \
+        } while (0)
+
+    DO_TEST(ReadConfigParam);
+
+    return result == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+VIRT_TEST_MAIN(mymain)
+
+#else
+
+int main(void)
+{
+    return EXIT_AM_SKIP;
+}
+
+#endif /* WITH_OPENVZ */