Upstream: fixed error handling of stale and revalidated cache send. The NGX_DONE value returned from ngx_http_upstream_cache_send() indicates that upstream was already finalized in ngx_http_upstream_process_headers(). It was treated as a generic error which resulted in duplicate finalization. Handled NGX_HTTP_UPSTREAM_INVALID_HEADER from ngx_http_upstream_cache_send(). Previously, it could return within ngx_http_upstream_finalize_request(), and since it's below NGX_HTTP_SPECIAL_RESPONSE, a client connection could stuck.

# Copyright (C) Nginx, Inc.


if [ $USE_THREADS = YES ]; then

    if [ "$NGX_PLATFORM" = win32 ]; then
        cat << END

$0: --with-threads is not supported on Windows

END
        exit 1
    fi

    have=NGX_THREADS . auto/have
    CORE_DEPS="$CORE_DEPS $THREAD_POOL_DEPS"
    CORE_SRCS="$CORE_SRCS $THREAD_POOL_SRCS"
    CORE_LIBS="$CORE_LIBS -lpthread"
fi