Found by Coverity.

The bug had appeared in 0.8.43 (r3653).  Patch by Weibin Yao.

Previous code incorrectly used ctx->var_values as an array of pointers to
ngx_http_variable_value_t, but the array contains structures, not pointers.
Additionally, ctx->var_values inspection failed to properly set var on
match.

Found by Coverity.

There is a general consensus that this change results in better
consistency between different operating systems and differently
tuned operating systems.

Note: this changes the width and meaning of the ipv6only field
of the ngx_listening_t structure.  3rd party modules that create
their own listening sockets might need fixing.

found.

Hide headers and pass headers arrays might not be inherited correctly
into a nested location, e.g. in configuration like

    server {
        proxy_hide_header X-Foo;
        location / {
            location /nested/ {
                proxy_pass_header X-Pad;
            }
        }
    }

the X-Foo header wasn't hidden in the location /nested/.

Reported by Konstantin Svist,
http://mailman.nginx.org/pipermail/nginx-ru/2012-July/047555.html