* environ.cc (dos_file_warning): Declare.

(parse_thing): Add "dosfilewarning".  Alphabetize.
* path.cc (normalize_posix_path): Return -1 when MS-DOS path detected.
(warn_msdos): New function.
(path_conv::check): Call if !PC_NOWARN and MS-DOS path detected.
(cygwin_conv_to_win32_path): Set PC_NOWARN when calling path_conv.
(cygwin_conv_to_full_win32_path): Ditto.
* path.h (pathconv_arg::PC_NOWARN): Define.
* shared_info.h (user_info::warned_msdos): New field.
(CURR_USER_MAGIC): Reset.

winsup/cygwin/path.h

@@ -47,6 +47,7 @@ enum pathconv_arg
   PC_NULLEMPTY		= 0x0020,
   PC_CHECK_EA		= 0x0040,
   PC_POSIX		= 0x0080,
+  PC_NOWARN		= 0x0100,
   PC_NO_ACCESS_CHECK	= 0x00800000
 };