why "if" can not be used within "if"?

[climbor]

Hello everyone,

I just noticed that "If" can only be used in very limited situations. It is far from the first impression it gave to me. So I did some code reading and found the reason. After adding NGX_HTTP_LIF_CONF flag to ngx_command_t "if", it worked. Then I can write some more complex rule set.

But I just wandering whether this could bring any consequence -- such as make nginx unstable or bring performance penalty?

Any clue will be appreciated.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,4419,4419#msg-4419