Resolver: fixed crashes in timeout handler. If one or more requests were waiting for a response, then after getting a CNAME response, the timeout event on the first request remained active, pointing to the wrong node with an empty rn->waiting list, and that could cause either null pointer dereference or use-after-free memory access if this timeout expired. If several requests were waiting for a response, and the first request terminated (e.g., due to client closing a connection), other requests were left without a timeout and could potentially wait indefinitely. This is fixed by introducing per-request independent timeouts. This change also reverts 954867a2f0a6 and 5004210e8c78.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


echo $ngx_n "checking for $ngx_lib ...$ngx_c"

cat << END >> $NGX_AUTOCONF_ERR

----------------------------------------
checking for $ngx_lib

END

ngx_found=no

cat << END > $NGX_AUTOTEST.c

$ngx_lib_incs

int main() {
    $ngx_lib_test;
    return 0;
}


eval "$CC $cc_test_flags $ngx_lib_cflags \
     -o $NGX_AUTOTEST $NGX_AUTOTEST.c $ngx_libs \
     >> $NGX_ERR 2>&1"

if [ -x $NGX_AUTOTEST ]; then
    echo " found"

    ngx_found=yes

else
    echo " not found"
fi

rm -rf $NGX_AUTOTEST*