Core: working_directory relative to prefix

Previously, a relative path was resolved against the current working
directory of the master process, which depends on how nginx is started.
Now it is resolved relative to prefix, similar to pid and error_log.

src/core/nginx.c

@@ -1231,6 +1231,13 @@ ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
                NGX_OLDPID_EXT, sizeof(NGX_OLDPID_EXT));
 
 
+    if (ccf->working_directory.len) {
+        if (ngx_conf_full_name(cycle, &ccf->working_directory, 0) != NGX_OK) {
+            return NGX_CONF_ERROR;
+        }
+    }
+
+
 #if !(NGX_WIN32)
 
     if (ccf->user == (uid_t) NGX_CONF_UNSET_UINT && geteuid() == 0) {