* Take care for the case where nkey is NULL

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1921067 13f79535-47bb-0310-9956-ffa450edef68

Author: rpluem

modules/cache/mod_cache_socache.c

@@ -700,9 +700,11 @@ static int open_entity(cache_handle_t *h, request_rec *r, const char *key)
             return DECLINED;
         }
     }
-    conf->provider->socache_provider->remove(
-            conf->provider->socache_instance, r->server,
-            (unsigned char *) nkey, strlen(nkey), r->pool);
+    if (nkey) {
+        conf->provider->socache_provider->remove(
+                conf->provider->socache_instance, r->server,
+                (unsigned char *) nkey, strlen(nkey), r->pool);
+    }
     if (socache_mutex) {
         apr_status_t status = apr_global_mutex_unlock(socache_mutex);
         if (status != APR_SUCCESS) {