Fixed alias in regex locations with limit_except/if. The ngx_http_map_uri_to_path() function used clcf->regex to detect if it's working within a location given by a regular expression and have to replace full URI with alias (instead of a part matching the location prefix). This is incorrect due to clcf->regex being false in implicit locations created by if and limit_except. Fix is to preserve relevant information in clcf->alias instead, by setting it to NGX_MAX_SIZE_T_VALUE if an alias was specified in a regex location.

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


ngx_include="unistd.h";      . auto/include
ngx_include="inttypes.h";    . auto/include
ngx_include="limits.h";      . auto/include
ngx_include="sys/filio.h";   . auto/include
ngx_include="sys/param.h";   . auto/include
ngx_include="sys/mount.h";   . auto/include
ngx_include="sys/statvfs.h"; . auto/include
ngx_include="crypt.h";       . auto/include