cgm_get: support NULL value

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

diff --git a/src/lxc/cgmanager.c b/src/lxc/cgmanager.c
index 2fa49a77b207c67dc11d6bc24ba3578fb21a785c..e43e1f7c777595ecf524f99f6e8aec2a26326948 100644 (file)
--- a/src/lxc/cgmanager.c
+++ b/src/lxc/cgmanager.c
@@ -269,6 +269,12 @@ int cgm_get(const char *filename, char *value, size_t len, const char *name, con
        }
        free(cgroup);
        newlen = strlen(result);
+       if (!value) {
+               // user queries the size
+               nih_free(result);
+               return newlen+1;
+       }
+
        strncpy(value, result, len);
        if (newlen >= len) {
                value[len-1] = '\0';