Fixed segfault when switching off master process during upgrade. Binary upgrades are not supported without master process, but it is, however, possible, that nginx running with master process is asked to upgrade binary, and the configuration file as available on disk at this time includes "master_process off;". If this happens, listening sockets inherited from the previous binary will have ls[i].previous set. But the old cycle on initial process startup, including startup after binary upgrade, is destroyed by ngx_init_cycle() once configuration parsing is complete. As a result, an attempt to dereference ls[i].previous in ngx_event_process_init() accesses already freed memory. Fix is to avoid looking into ls[i].previous if the old cycle is already freed. With this change it is also no longer needed to clear ls[i].previous in worker processes, so the relevant code was removed.

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


have=NGX_WIN32 . auto/have_headers

CORE_INCS="$WIN32_INCS"
CORE_DEPS="$WIN32_DEPS"
CORE_SRCS="$WIN32_SRCS $IOCP_SRCS"
OS_CONFIG="$WIN32_CONFIG"
NGX_ICONS="$NGX_WIN32_ICONS"
SELECT_SRCS=$WIN32_SELECT_SRCS
POLL_SRCS=$WIN32_POLL_SRCS

ngx_pic_opt=
ngx_binext=".exe"

case "$NGX_CC_NAME" in

    gcc)
        CORE_LIBS="$CORE_LIBS -ladvapi32 -lws2_32"
        MAIN_LINK="$MAIN_LINK -Wl,--export-all-symbols"
        MAIN_LINK="$MAIN_LINK -Wl,--out-implib=$NGX_OBJS/libnginx.a"
        MODULE_LINK="-shared -L $NGX_OBJS -lnginx"
    ;;

    *)
        CORE_LIBS="$CORE_LIBS advapi32.lib ws2_32.lib"
    ;;

esac

EVENT_MODULES="$EVENT_MODULES $IOCP_MODULE"
#EVENT_FOUND=YES

have=NGX_HAVE_INET6 . auto/have

have=NGX_HAVE_IOCP . auto/have