*) check a proxy_redirect single parameter
*) warn about "proxy_redirect false"

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 628b32d..fc67a67 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -2675,10 +2675,26 @@
 
     value = cf->args->elts;
 
-    if (ngx_strcmp(value[1].data, "off") == 0) {
-        plcf->redirect = 0;
-        plcf->redirects = NULL;
-        return NGX_CONF_OK;
+    if (cf->args->nelts == 2) {
+        if (ngx_strcmp(value[1].data, "off") == 0) {
+            plcf->redirect = 0;
+            plcf->redirects = NULL;
+            return NGX_CONF_OK;
+        }
+
+        if (ngx_strcmp(value[1].data, "false") == 0) {
+            ngx_conf_log_error(NGX_LOG_ERR, cf, 0,
+                           "invalid parameter \"false\", use \"off\" instead");
+            plcf->redirect = 0;
+            plcf->redirects = NULL;
+            return NGX_CONF_OK;
+        }
+
+        if (ngx_strcmp(value[1].data, "default") != 0) {
+            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                               "invalid parameter \"%V\"", &value[1]);
+            return NGX_CONF_ERROR;
+        }
     }
 
     if (plcf->redirects == NULL) {
@@ -2694,7 +2710,7 @@
         return NGX_CONF_ERROR;
     }
 
-    if (cf->args->nelts == 2 && ngx_strcmp(value[1].data, "default") == 0) {
+    if (ngx_strcmp(value[1].data, "default") == 0) {
         if (plcf->url.data == NULL) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                "\"proxy_rewrite_location default\" must go "