[mod_proxy] fix segfault in Set-Cookie reverse map (fixes #2879)
[mod_proxy] fix segfault in Set-Cookie reverse map (fixes #2879)

fix segfault in reverse url-path mapping of Set-Cookie sent from backend
when proxy.header = ( "map-urlpath" => ( ... ) ) is used and there are
multiple Set-Cookie response headers with path= attributes which need to
be reverse mapped.

(thx ganto)

x-ref:
  "Segfault with proxy-header map-urlpath"
  https://redmine.lighttpd.net/issues/2879

lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4