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.


if [ $PCRE != NONE -a $PCRE != NO -a $PCRE != YES ]; then
    . auto/lib/pcre/make
fi

if [ $MD5 != NONE -a $MD5 != NO -a $MD5 != YES ]; then
    . auto/lib/md5/make
fi

if [ $SHA1 != NONE -a $SHA1 != NO -a $SHA1 != YES ]; then
    . auto/lib/sha1/make
fi

if [ $OPENSSL != NONE -a $OPENSSL != NO -a $OPENSSL != YES ]; then
    . auto/lib/openssl/make
fi

if [ $ZLIB != NONE -a $ZLIB != NO -a $ZLIB != YES ]; then
    . auto/lib/zlib/make
fi

if [ $NGX_LIBATOMIC != NO -a $NGX_LIBATOMIC != YES ]; then
    . auto/lib/libatomic/make
fi

if [ $USE_PERL = YES ]; then
    . auto/lib/perl/make
fi