[PATCH 3 of 5] Fix double content when return is used in error_page redirection

[Maxim Dounin]

Hello!

On Tue, Nov 02, 2010 at 06:57:33AM +0300, Maxim Dounin wrote:

> # HG changeset patch
> # User Maxim Dounin <mdounin at mdounin.ru>
> # Date 1288669813 -10800
> # Node ID 7ec15c9b1a6e7046334aabc09c907c7601ddbfdc
> # Parent  49670f58d178cbef2108a76676b8d79cf2cb648b
> Fix double content when return is used in error_page redirection.
> 
> Test case:
> 
>    location / {
>        error_page 405 /nope;
>        return 405;
>    }
> 
>    location /nope {
>        return 200;
>    }
> 
> This is expected to return 405 with empty body, but in 0.8.42+ will return
> builtin 405 error page as well (though not counted in Content-Length, thus
> breaking protocol).
> 
> Note that this patch also changes behaviour for "return 302 ..." and
> "rewrite ... redirect" used as error handler.  E.g.
> 
>     location / {
>         error_page 405 /redirect;
>         return 405;
>     }
> 
>     location /redirect {
>         rewrite ^ http://example.com/;
>     }
> 
> will actually return redirect to "http://example.com/" instead of builtin 405
> error page with meaningless Location header.  This looks like correct change
> and it's in line with what happens on e.g. directory redirects in error
> handlers.
> 
> diff --git a/src/http/modules/ngx_http_rewrite_module.c b/src/http/modules/ngx_http_rewrite_module.c
> --- a/src/http/modules/ngx_http_rewrite_module.c
> +++ b/src/http/modules/ngx_http_rewrite_module.c
> @@ -167,15 +167,7 @@ ngx_http_rewrite_handler(ngx_http_reques
>          code(e);
>      }
>  
> -    if (e->status == NGX_DECLINED) {
> -        return NGX_DECLINED;
> -    }
> -
> -    if (r->err_status == 0) {
> -        return e->status;
> -    }
> -
> -    return r->err_status;
> +    return e->status;
>  }

Forget this one, it's wrong as it breaks

    location /return405 {
        return 405;
    }

    location /error404return405 {
        error_page 404 /return405;
        return 404;
    }

test case (should return 404 status code for 
"/error404return405").

Updated patch:

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1288675107 -10800
# Node ID 39827c7c5c0191aec623b632aacf07e6783be1ce
# Parent  49670f58d178cbef2108a76676b8d79cf2cb648b
Fix double content when return is used in error_page redirection.

Test case:

   location / {
       error_page 405 /nope;
       return 405;
   }

   location /nope {
       return 200;
   }

This is expected to return 405 with empty body, but in 0.8.42+ will return
builtin 405 error page as well (though not counted in Content-Length, thus
breaking protocol).

Note that this patch also changes behaviour for "return 302 ..." and
"rewrite ... redirect" used as error handler.  E.g.

    location / {
        error_page 405 /redirect;
        return 405;
    }

    location /redirect {
        rewrite ^ http://example.com/;
    }

will actually return redirect to "http://example.com/" instead of builtin 405
error page with meaningless Location header.  This looks like correct change
and it's in line with what happens on e.g. directory redirects in error
handlers.

diff --git a/src/http/modules/ngx_http_rewrite_module.c b/src/http/modules/ngx_http_rewrite_module.c
--- a/src/http/modules/ngx_http_rewrite_module.c
+++ b/src/http/modules/ngx_http_rewrite_module.c
@@ -167,8 +167,8 @@ ngx_http_rewrite_handler(ngx_http_reques
         code(e);
     }
 
-    if (e->status == NGX_DECLINED) {
-        return NGX_DECLINED;
+    if (e->status < NGX_HTTP_BAD_REQUEST) {
+        return e->status;
     }
 
     if (r->err_status == 0) {


Maxim Dounin