Capture in if - escaping depends on location bug

Server NGINX
1

I am capturing some data in if, and then redirecting on what was
captured. The problem is, that captured data is escaped if url contains
“%” char, and may be others, and do not escaped if it does not. I have
simple config:

Having simple config

location / {
    set $out "http://example.com/?a=b&c=d%";
   if ( $out ~ "(.*)" ){
        set $z $1;
        rewrite ^ $z redirect;
    }

Making 2 requests:

telnet 127.0.0.1 80
Trying 127.0.0.1…
Connected to 127.0.0.1.
Escape character is ‘^]’.
GET / HTTP/1.0
Host: my.ru

HTTP/1.1 302 Moved Temporarily
Server: nginx/1.0.14
Date: Thu, 22 Mar 2012 02:20:14 GMT
Content-Type: text/html
Content-Length: 161
Connection: close
Location: Example Domain

302 Found

302 Found

nginx/1.0.14 Connection closed by foreign host.

telnet 127.0.0.1 80
Trying 127.0.0.1…
Connected to 127.0.0.1.
Escape character is ‘^]’.
GET /% HTTP/1.0
Host: my.ru

HTTP/1.1 302 Moved Temporarily
Server: nginx/1.0.14
Date: Thu, 22 Mar 2012 02:21:00 GMT
Content-Type: text/html
Content-Length: 161
Connection: close
Location: Example Domain

302 Found

302 Found

nginx/1.0.14 Connection closed by foreign host.

Expected the same location as in first request, but got another.
Tested on nginx-1.0.14 , nginx-1.0.6 .

Posted at Nginx Forum: