Windows: include= and exclude= containing '/' will also match filenames that are written using '\'

And vice-versa, but it's better to use '/' for portability.

Notably, standardPreferredContent contains "archive/*" and that might not
match if the filename ends up coming in with the slashes the other way
around.

Utility/Glob.hs

@@ -1,15 +1,17 @@
-{-# LANGUAGE PackageImports #-}
-
 {- file globbing
  -
- - Copyright 2014 Joey Hess <id@joeyh.name>
+ - Copyright 2014-2020 Joey Hess <id@joeyh.name>
  -
  - License: BSD-2-clause
  -}
 
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE PackageImports #-}
+
 module Utility.Glob (
 	Glob,
 	GlobCase(..),
+	GlobFilePath(..),
 	compileGlob,
 	matchGlob
 ) where
@@ -24,26 +26,42 @@ newtype Glob = Glob Regex
 
 data GlobCase = CaseSensative | CaseInsensative
 
+-- Is the glob being used to match filenames? 
+--
+-- When matching filenames,
+-- a single path separator (eg /) in the glob will match any
+-- number of path separators in the filename.
+-- And on Windows, both / and \ are used as path separators, so compile
+-- the glob to a regexp that matches either path separator.
+newtype GlobFilePath = GlobFilePath Bool
+
 {- Compiles a glob to a regex, that can be repeatedly used. -}
-compileGlob :: String -> GlobCase -> Glob
-compileGlob glob globcase = Glob $
+compileGlob :: String -> GlobCase -> GlobFilePath -> Glob
+compileGlob glob globcase globfilepath = Glob $
 	case compile (defaultCompOpt {caseSensitive = casesentitive}) defaultExecOpt regex of
 		Right r -> r
 		Left _ -> giveup $ "failed to compile regex: " ++ regex
   where
-	regex = '^' : wildToRegex glob ++ "$"
+	regex = '^' : wildToRegex globfilepath glob ++ "$"
 	casesentitive = case globcase of
 		CaseSensative -> True
 		CaseInsensative -> False
 
-wildToRegex :: String -> String
-wildToRegex = concat . go
+wildToRegex :: GlobFilePath -> String -> String
+wildToRegex (GlobFilePath globfile) = concat . go
   where
 	go [] = []
 	go ('*':xs) = ".*" : go xs
 	go ('?':xs) = "." : go xs
 	go ('[':'!':xs) = "[^" : inpat xs
 	go ('[':xs) = "[" : inpat xs
+#ifdef mingw32_HOST_OS
+	go ('/':xs) | globfile = "[/\\]+" : go xs
+	go ('\\':xs) | globfile = "[/\\]+" : go xs
+#else
+	go ('/':xs) | globfile = "[/]+" : go xs
+	go ('\\':xs) | globfile = "[\\]+" : go xs
+#endif
 	go (x:xs)
 		| isDigit x || isAlpha x = [x] : go xs
 		| otherwise = esc x : go xs