Merge of r4948, r4949, r4964, r4973, r5011: variables. *) Allow the complex value to be defined as an empty string. This makes conversion from strings to complex values possible without the loss of functionality. *) The "auth_basic" directive gained support of variables. *) Fixed variable syntax checking in "set", "geo", "limit_conn_zone", and "perl_set" directives. *) Added checks that disallow adding a variable with an empty name. Added variable name syntax checks to "geo" and "map" directives. *) Variables $pipe, $request_length, $time_iso8601, and $time_local. Log module counterparts are preserved for efficiency. Based on patch by Kiril Kalchev.

--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -836,7 +836,7 @@ ngx_http_proxy_create_key(ngx_http_reque
         return NGX_ERROR;
     }
 
-    if (plcf->cache_key.value.len) {
+    if (plcf->cache_key.value.data) {
 
         if (ngx_http_complex_value(r, &plcf->cache_key, key) != NGX_OK) {
             return NGX_ERROR;
@@ -3918,7 +3918,7 @@ ngx_http_proxy_cache_key(ngx_conf_t *cf,
 
     value = cf->args->elts;
 
-    if (plcf->cache_key.value.len) {
+    if (plcf->cache_key.value.data) {
         return "is duplicate";
     }