Proxy: support variables for proxy_method directive.

src/http/modules/ngx_http_proxy_module.c

diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 480e974..5a686a3 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -73,7 +73,7 @@
     ngx_array_t                   *cookie_domains;
     ngx_array_t                   *cookie_paths;
 
-    ngx_str_t                      method;
+    ngx_http_complex_value_t      *method;
     ngx_str_t                      location;
     ngx_str_t                      url;
 
@@ -380,7 +380,7 @@
 
     { ngx_string("proxy_method"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
-      ngx_conf_set_str_slot,
+      ngx_http_set_complex_value_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_proxy_loc_conf_t, method),
       NULL },
@@ -1159,8 +1159,10 @@
         /* HEAD was changed to GET to cache response */
         method = u->method;
 
-    } else if (plcf->method.len) {
-        method = plcf->method;
+    } else if (plcf->method) {
+        if (ngx_http_complex_value(r, plcf->method, &method) != NGX_OK) {
+            return NGX_ERROR;
+        }
 
     } else {
         method = r->method_name;
@@ -2797,7 +2799,7 @@
      *     conf->upstream.store_values = NULL;
      *     conf->upstream.ssl_name = NULL;
      *
-     *     conf->method = { 0, NULL };
+     *     conf->method = NULL;
      *     conf->headers_source = NULL;
      *     conf->headers.lengths = NULL;
      *     conf->headers.values = NULL;
@@ -3158,7 +3160,9 @@
 
 #endif
 
-    ngx_conf_merge_str_value(conf->method, prev->method, "");
+    if (conf->method == NULL) {
+        conf->method = prev->method;
+    }
 
     ngx_conf_merge_value(conf->upstream.pass_request_headers,
                               prev->upstream.pass_request_headers, 1);