From 94adeb1d13889b6b6dfd36135889c0e921d3582b Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Thu, 23 Nov 2006 01:50:34 +0000
Subject: [PATCH] make more path tests run on all platforms, use
 system-idle-evt for some sync tests

svn: r4926
---
 collects/tests/mzscheme/expand.ss |   2 +-
 collects/tests/mzscheme/path.ss   | 584 +++++++++++++++++-------------
 collects/tests/mzscheme/sync.ss   |  48 +--
 collects/tests/mzscheme/thread.ss |  10 +-
 4 files changed, 361 insertions(+), 283 deletions(-)

diff --git a/collects/tests/mzscheme/expand.ss b/collects/tests/mzscheme/expand.ss
index 0ed268da8d..f850a8704c 100644
--- a/collects/tests/mzscheme/expand.ss
+++ b/collects/tests/mzscheme/expand.ss
@@ -125,7 +125,7 @@
  'expand-load
  #f
  (lambda ()
-   (namespace-set-variable-value! 'expand-load "quiet.ss")))
+   (namespace-set-variable-value! 'expand-load "mz.ss")))
 
 (let ([orig (current-eval)])
   (dynamic-wind
diff --git a/collects/tests/mzscheme/path.ss b/collects/tests/mzscheme/path.ss
index a02d01a931..24e541a363 100644
--- a/collects/tests/mzscheme/path.ss
+++ b/collects/tests/mzscheme/path.ss
@@ -418,8 +418,6 @@
 		(path->string
 		 (normal-case-path (simplify-path (expand-path (current-directory))))))
 	       "")]
-	[get-base (lambda (s)
-		    (let-values ([(base name dir?) (split-path s)]) (list base name)))]
 	[drive (path->string (current-drive))])
 
     (test #t directory-exists? here)
@@ -480,185 +478,6 @@
       (test (string->path "\\\\?\\REL\\a\\\\\\a") path->complete-path "\\a")
       )
 
-    (test (bytes->path #"c:\\a") path->complete-path "\\a" "c:")
-    (test (bytes->path #"\\\\foo\\bar\\a") path->complete-path "\\a" "\\\\foo\\bar\\a")
-
-    ;; Build path collapses .. and . in added parts and cleans up slashes and trailers:
-    (test (string->path "\\\\?\\c:\\a\\b") build-path "\\\\?\\c:\\a" 'same "b")
-    (test (string->path "\\\\?\\c:\\a\\b") build-path "\\\\?\\c:\\a\\" 'same "b")
-    (test (string->path "\\\\?\\c:\\a\\.\\b") build-path "\\\\?\\c:\\a\\." 'same "b")
-    (test (string->path "\\\\?\\c:\\a\\.\\b") build-path "\\\\?\\c:\\a\\.\\" 'same "b")
-    (test (string->path "\\\\?\\c:\\b") build-path "\\\\?\\c:\\a\\" 'up "b")
-    (test (string->path "\\\\?\\c:\\a\\b") build-path "\\\\?\\c:\\a\\.\\" 'up "b")
-    (test (string->path "\\\\?\\c:\\b") build-path "\\\\?\\c:\\a\\.\\" 'up 'up 'up "b")
-    (test (string->path "\\\\?\\c:\\a\\b\\c\\d\\f\\") build-path "\\\\?\\c:\\a" "b//c" "d//\\f///")
-    (test (string->path "\\\\?\\c:\\a\\foo") build-path "\\\\?\\c:\\a" "foo...  ")
-
-    (test (string->path "\\\\?\\REL\\\\a") build-path "." "\\\\?\\REL\\a")
-    (test (string->path "\\\\?\\REL\\\\a") build-path 'same "\\\\?\\REL\\a")
-    (test (string->path "\\\\?\\REL\\\\a\\") build-path "\\\\?\\REL\\a" 'same)
-    (test (string->path ".") build-path "\\\\?\\REL\\a" 'up)
-    (test (string->path "\\\\?\\REL\\\\apple") build-path "\\\\?\\REL\\a" 'up "apple")
-    (test (string->path ".") build-path "\\\\?\\REL\\a" 'up 'same)
-
-    (test (string->path "\\\\?\\REL\\..\\\\a") build-path 'up "\\\\?\\REL\\a")
-    (test (string->path "\\\\?\\REL\\..\\\\..") build-path 'up "\\\\?\\REL\\\\..")
-    (test (string->path "\\\\?\\REL\\..\\..") build-path 'up "\\\\?\\REL\\..")
-    (test (string->path "\\\\?\\REL\\..\\..") build-path "\\\\?\\REL\\.." 'up)
-    (test (string->path "\\\\?\\REL\\..\\..\\..") build-path 'up "\\\\?\\REL\\.." 'up)
-    (test (string->path "\\\\?\\REL\\..\\..\\\\..") build-path 'up "\\\\?\\REL\\.." "\\\\?\\REL\\\\..")
-    (test (string->path "\\\\?\\REL\\..\\..") build-path 'up "\\\\?\\REL\\.." "\\\\?\\REL\\\\.." 'up)
-    (test (string->path "\\\\?\\REL\\\\..\\") build-path "\\\\?\\REL\\\\.." "\\\\?\\REL\\\\.." 'up)
-    (test (string->path "\\\\?\\REL\\\\x\\") build-path "x/y" "\\\\?\\REL\\..")
-    (test (string->path "\\\\?\\c:\\x\\") build-path "c:x/y" "\\\\?\\REL\\..")
-
-    (test-values (list (string->path "\\\\?\\REL\\..")
-		       (string->path "\\\\?\\REL\\\\a")
-		       #f)
-		 (lambda () (split-path "\\\\?\\REL\\..\\a")))
-    (test-values (list (string->path "\\\\?\\REL\\..")
-		       (string->path "\\\\?\\REL\\\\a")
-		       #f)
-		 (lambda () (split-path "\\\\?\\REL\\..\\\\a")))
-    (test-values (list (string->path "\\\\?\\REL\\b\\")
-		       (string->path "\\\\?\\REL\\\\a")
-		       #f)
-		 (lambda () (split-path "\\\\?\\REL\\b\\a")))
-
-    (test (string->path "\\\\?\\UNC\\f\\g") build-path "//f/g/h" "\\\\?\\REL\\..")
-    (test (string->path "\\\\?\\UNC\\f\\g\\h\\") build-path "//f/g/h/i" "\\\\?\\REL\\..")
-    (test (string->path "\\\\?\\UNC\\f\\g\\h\\..") build-path "//f/g/h" "\\\\?\\REL\\\\..")
-    (test (string->path "\\\\?\\UNC\\f\\g\\h\\..") build-path "//f/g//h" "\\\\?\\REL\\\\..")
-    (test (string->path "\\\\?\\UNC\\f\\g\\i\\x") build-path "//f/g/h/../i" "\\\\?\\REL\\x")
-    (test (string->path "\\\\?\\UNC\\f\\g\\h\\i\\x") build-path "//f/g/../h/i" "\\\\?\\REL\\x")
-
-    (test (string->path (string-append "\\\\?\\" drive "f\\g\\")) build-path "/f/g/h" "\\\\?\\REL\\..")
-    (test (string->path (string-append "\\\\?\\" drive "f\\g\\h\\x")) build-path "/f/g/h" "\\\\?\\REL\\x")
-    (test (string->path (string-append "\\\\?\\" drive "f\\g\\h\\x")) build-path "//f//g/h" "\\\\?\\REL\\x")
-    (test (string->path (string-append "\\\\?\\" drive "f\\g\\h\\x")) build-path "/f//g////h" "\\\\?\\REL\\x")
-    (test (string->path (string-append "\\\\?\\" drive)) build-path "/f//g////h" "\\\\?\\REL\\..\\..\\..\\..")
-    (test (string->path (string-append "\\\\?\\" drive "?\\g\\h\\x")) build-path "//?/g/h" "\\\\?\\REL\\x")
-
-    ;; Allow \\?\ as a drive to add an absolute path:
-    (test (string->path "\\\\?\\c:\\b") build-path "\\\\?\\c:\\" "\\b")
-    (test (string->path "\\\\?\\c:\\b") build-path "\\\\?\\c:\\\\" "\\b")
-    (test (string->path "\\\\?\\c:\\b\\") build-path "\\\\?\\c:\\\\" "\\b\\")
-    (test (string->path "\\\\?\\UNC\\goo\\bar\\b") build-path "\\\\?\\UNC\\goo\\bar" "\\b")
-    (test (string->path "\\\\?\\\\b") build-path "\\\\?\\" "\\b")
-    (test (string->path "\\\\?\\\\b\\") build-path "\\\\?\\" "\\b\\")
-    (err/rt-test (build-path "\\\\?\\c:" "\\b") exn:fail:contract?)
-    
-    ;; Don't allow path addition on bad \\?\ to change the root:
-    (test (string->path "\\\\?\\\\c") build-path "\\\\?\\" "c")
-    (test (string->path "\\\\?\\\\UNC") build-path "\\\\?\\" "UNC")
-    (test (string->path "\\\\?\\\\UNC\\s\\y") build-path "\\\\?\\UNC" "s/y")
-    (test (string->path "\\\\?\\\\UNC\\s\\y") build-path "\\\\?\\UNC\\" "s/y")
-    (test (string->path "\\\\?\\\\REL\\s\\y") build-path "\\\\?\\REL" "s/y")
-    (test (string->path "\\\\?\\\\REL\\s\\y") build-path "\\\\?\\REL\\" "s/y")
-    (test (string->path "\\\\?\\REL\\\\\\s\\y") build-path "\\\\?\\REL\\\\" "s/y")
-    (test (string->path "\\\\?\\REL\\x\\\\\\z") build-path "\\\\?\\REL\\x\\\\" "z")
-    (test (string->path "/apple\\x") build-path "//apple" "x")
-    (test (string->path "\\\\?") build-path "\\\\" "?")
-    (test (string->path "\\?\\") build-path "\\\\" "?\\")
-    (test (string->path "\\?\\a") build-path "\\\\" "?" "a")
-    (test (string->path "\\?\\a") build-path "\\\\?" "a")
-    (test (string->path "\\?\\a\\") build-path "\\\\?" "a\\")
-    (test (string->path "\\\\?\\\\c:") build-path "\\\\?\\" "\\\\?\\REL\\c:")
-    (test (string->path "\\\\?\\\\c:\\a") build-path "\\\\?\\" "\\\\?\\REL\\c:\\a")
-    (test (string->path "\\\\?\\\\REL\\b") build-path "\\\\?\\" "\\\\?\\REL\\REL\\b")
-    (test (string->path "\\\\?\\\\host\\vol\\a\\") build-path "\\\\?\\" "\\\\?\\REL\\\\host\\vol\\a\\")
-
-    ;; UNC paths can't have "?" for machine or "/" in machine part:
-    (test (list (string->path "/?/") (string->path "x")) get-base "//?/x")
-    (test (list (string->path "\\\\?\\UNC\\a/b\\") (string->path "x")) get-base "\\\\?\\UNC\\a/b\\x")
-
-    ;; Split path must treat \\?\ part as a root:
-    (test (list (string->path "\\\\?\\c:\\") (string->path "a")) get-base "\\\\?\\c:\\a")
-    (test (list (string->path "\\\\?\\") (string->path "\\\\?\\REL\\\\c:")) get-base "\\\\?\\c:")
-    (test (list #f (string->path "\\\\?\\c:\\")) get-base "\\\\?\\c:\\")
-    (test (list #f (string->path "\\\\?\\c:\\\\")) get-base "\\\\?\\c:\\\\")
-    (test (list (string->path "\\\\?\\c:\\") (string->path "a")) get-base "\\\\?\\c:\\\\a")
-    (test (list #f (string->path "\\\\?\\UNC\\mach\\vol")) get-base "\\\\?\\UNC\\mach\\vol")
-    (test (list #f (string->path "\\\\?\\UNC\\mach\\\\vol")) get-base "\\\\?\\UNC\\mach\\\\vol")
-    (test (list #f (string->path "\\\\?\\UNC\\\\mach\\vol")) get-base "\\\\?\\UNC\\\\mach\\vol")
-    (test (list (string->path "\\\\?\\") (string->path "c")) get-base "\\\\?\\c")
-    (test (list (string->path "\\\\?\\UNC\\") (string->path "x")) get-base "\\\\?\\UNC\\x")
-    (test (list (string->path "\\\\?\\") (string->path "UNC")) get-base "\\\\?\\UNC\\")
-    (test (list #f (string->path "\\\\?\\UNC\\\\")) get-base "\\\\?\\UNC\\\\")
-    (test (list #f (string->path "\\\\?\\xyz\\\\")) get-base "\\\\?\\xyz\\\\")
-    (test (list (string->path "\\\\?\\c:\\a\\\\") (string->path "b")) get-base "\\\\?\\c:\\a\\\\\\b\\")
-    (test (list #f (string->path "\\\\?\\c:\\a\\\\\\")) get-base "\\\\?\\c:\\a\\\\\\")
-    (test (list (string->path "\\\\?\\UNC\\") (string->path "\\\\?\\REL\\\\x/y")) get-base "\\\\?\\UNC\\x/y")
-    (test (list #f (string->path "\\\\?\\UNC\\x\\y")) get-base "\\\\?\\UNC\\x\\y")
-    (test (list (string->path "\\\\?\\REL\\\\x\\y ") (string->path "z")) get-base "x/y /z")
-    (test (list (string->path "\\\\?\\REL\\\\y ") (string->path "z")) get-base "x/../y /z")
-    (test (list (string->path "\\\\?\\REL\\..\\\\y ") (string->path "z")) get-base "../y /z")
-    (test (list (string->path "\\\\?\\c:\\y ") (string->path "z")) get-base "c:/y /z")
-    (test (list (string->path "\\\\?\\c:\\y ") (string->path "z")) get-base "c:/../y /z")
-    (test (list (string->path "../aux/") (string->path "z")) get-base "../aux/z")
-    (test (list (string->path "../aux.m/") (string->path "z")) get-base "../aux.m/z")
-    (test (list (string->path "..") (string->path "\\\\?\\REL\\\\aux.m")) get-base "../aux.m/")
-    (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux.m")) get-base "c:/aux.m/")
-    (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux.m.p")) get-base "c:/aux.m.p/")
-    (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux:m")) get-base "c:/aux:m/")
-    (test (list (string->path "..") (string->path "aux.m")) get-base "../aux.m")
-    
-    ;; simplify-path leaves literal . and .. alone:
-    (test (string->path "\\\\?\\c:\\b\\.\\..\\a") simplify-path "\\\\?\\c:\\b\\.\\..\\a")
-    (test (string->path "\\\\?\\c:\\B\\.\\..\\a") normal-case-path "\\\\?\\c:\\B\\.\\..\\a")
-    (test (string->path "\\\\?\\UNC\\foo\\A") normal-case-path "\\\\?\\UNC\\foo\\A")
-
-    ;; expand-path removes redundant backslashes, and
-    (test (string->path "\\\\?\\\\UNC\\x\\y") expand-path "\\\\?\\\\UNC\\x\\y")
-    (test (string->path "\\\\?\\c:\\") expand-path "\\\\?\\c:\\\\")
-
-    ;; expand-path removes redundant backslashes, and
-    ;; simplify-path uses expand-path under Windows:
-    (let ([go
-           (lambda (expand-path)
-             (test (string->path "c:\\") expand-path "c:")
-             (test (string->path "C:/") expand-path "C://")
-             (test (string->path "C:/a/") expand-path "C://a//")
-             (test (string->path "\\\\?\\c:\\a\\.") expand-path "\\\\?\\c:\\\\a\\\\.")
-             (test (string->path "\\\\?\\c:\\a\\\\") expand-path "\\\\?\\c:\\a\\\\")
-             (test (string->path "\\\\?\\c:\\a\\.") expand-path "\\\\?\\c:\\a\\\\.")
-             (test (string->path "\\\\?\\UNC\\a\\b\\.") expand-path "\\\\?\\UNC\\\\a\\b\\.")
-             (test (string->path "\\\\?\\UNC\\a\\b\\.") expand-path "\\\\?\\UNC\\\\a\\b\\\\.")
-             (test (string->path "\\\\?\\") expand-path "\\\\?\\\\"))])
-      (go expand-path)
-      (go simplify-path))
-
-    (test (bytes->path #"..") simplify-path "\\\\?\\REL\\..")
-    (test (bytes->path #"..") simplify-path "\\\\?\\REL\\..\\")
-    (test (bytes->path #"\\\\foo\\bar\\") expand-path "\\\\foo\\bar\\")
-    (test (bytes->path #"\\\\foo\\bar") simplify-path "\\\\foo\\bar\\")
-    (test (bytes->path #"\\\\foo\\bar") simplify-path "\\\\?\\UNC\\foo\\bar")
-    (test (bytes->path #"\\\\foo\\bar") simplify-path "\\\\?\\UNC\\foo\\bar\\")
-    (test (bytes->path #"\\\\?\\UNC\\foo\\bar\\..") simplify-path "\\\\?\\UNC\\foo\\bar\\..")
-    (test (bytes->path #"\\\\?\\UNC\\foo\\bar\\..\\") simplify-path "\\\\?\\UNC\\foo\\bar\\..\\")
-    (test (bytes->path #"a") simplify-path "\\\\?\\REL\\a")
-    (test (bytes->path #"a") simplify-path "\\\\?\\REL\\\\a")
-    (test (bytes->path #"a\\") simplify-path "\\\\?\\REL\\\\a\\")
-    (test (bytes->path #"\\\\?\\REL\\\\a/") simplify-path "\\\\?\\REL\\\\a/")
-    (test (bytes->path #"\\\\?\\REL\\\\..") simplify-path "\\\\?\\REL\\\\..")
-    (test (bytes->path #"\\\\?\\REL\\\\..\\") simplify-path "\\\\?\\REL\\\\..\\")
-    (test (bytes->path #"a \\b") simplify-path "\\\\?\\REL\\\\a \\b")
-    (test (bytes->path #"\\\\?\\REL\\\\aux.bad\\b") simplify-path "\\\\?\\REL\\aux.bad\\b")
-    (test (bytes->path #"\\\\?\\REL\\\\a\\b  ") simplify-path "\\\\?\\REL\\a\\b  ")
-    (test (bytes->path #"\\\\?\\REL\\\\.\\b") simplify-path "\\\\?\\REL\\.\\b")
-    (test (bytes->path #"\\\\?\\REL\\\\.") simplify-path "\\\\?\\REL\\.")
-    (test (bytes->path #"\\\\?\\REL\\\\:\\b") simplify-path "\\\\?\\REL\\:\\b")
-    (test (bytes->path #"\\\\?\\REL\\\\:") simplify-path "\\\\?\\REL\\:")
-    (test (bytes->path #"\\\\?\\REL") simplify-path "\\\\?\\REL")
-    (test (bytes->path #"C:\\a\\b") simplify-path "\\\\?\\C:\\a\\b")
-    (test (bytes->path #"C:\\a") simplify-path "\\\\?\\C:\\a")
-    (test (bytes->path #"\\\\?\\C:\\a ") simplify-path "\\\\?\\C:\\a ")
-    (test (bytes->path #"\\\\?\\C:a\\b") simplify-path "\\\\?\\C:a\\b")
-    (test (bytes->path #"\\\\?\\C:") simplify-path "\\\\?\\C:")
-    (test (bytes->path #"\\\\?\\a\\y") simplify-path "\\\\?\\a\\y")
-    (test (bytes->path #"\\\\?\\REL\\a\\y\\\\") simplify-path "\\\\?\\REL\\a\\y\\\\")
-    (test (bytes->path #"\\\\?\\REL\\a\\\\\\y") simplify-path "\\\\?\\REL\\a\\\\\\y")
-
     (let ([dir (build-path here "tmp78")])
       (unless (directory-exists? dir)
 	(make-directory dir))
@@ -670,81 +489,340 @@
 
     ))
 
+(let* ([bytes->path (lambda (p)
+                      (bytes->path p 'windows))]
+       [string->path (if (eq? (system-path-convention-type) 'windows)
+                         string->path
+                         (lambda (p)
+                           (bytes->path (string->bytes/latin-1 p))))]
+       [coerce (if (eq? (system-path-convention-type) 'windows)
+                   values
+                   string->path)]
+       [get-base (lambda (s)
+		    (let-values ([(base name dir?) (split-path s)]) (list base name)))])
+  (test (bytes->path #"c:\\a") path->complete-path (coerce "\\a") (coerce "c:"))
+  (test (bytes->path #"\\\\foo\\bar\\a") path->complete-path (coerce "\\a") (coerce "\\\\foo\\bar\\a"))
+  
+  ;; Build path collapses .. and . in added parts and cleans up slashes and trailers:
+  (test (string->path "\\\\?\\c:\\a\\b") build-path (coerce "\\\\?\\c:\\a") 'same (coerce "b"))
+  (test (string->path "\\\\?\\c:\\a\\b") build-path (coerce "\\\\?\\c:\\a\\") 'same (coerce "b"))
+  (test (string->path "\\\\?\\c:\\a\\.\\b") build-path (coerce "\\\\?\\c:\\a\\.") 'same (coerce "b"))
+  (test (string->path "\\\\?\\c:\\a\\.\\b") build-path (coerce "\\\\?\\c:\\a\\.\\") 'same (coerce "b"))
+  (test (string->path "\\\\?\\c:\\b") build-path (coerce "\\\\?\\c:\\a\\") 'up (coerce "b"))
+  (test (string->path "\\\\?\\c:\\a\\b") build-path (coerce "\\\\?\\c:\\a\\.\\") 'up (coerce "b"))
+  (test (string->path "\\\\?\\c:\\b") build-path (coerce "\\\\?\\c:\\a\\.\\") 'up 'up 'up (coerce "b"))
+  (test (string->path "\\\\?\\c:\\a\\b\\c\\d\\f\\") build-path (coerce "\\\\?\\c:\\a") (coerce "b//c") (coerce "d//\\f///"))
+  (test (string->path "\\\\?\\c:\\a\\foo") build-path (coerce "\\\\?\\c:\\a") (coerce "foo...  "))
+
+  (test (string->path "\\\\?\\REL\\\\a") build-path (coerce ".") (coerce "\\\\?\\REL\\a"))
+  (test (string->path "\\\\?\\REL\\\\a") build-path 'same (coerce "\\\\?\\REL\\a"))
+  (test (string->path "\\\\?\\REL\\\\a\\") build-path (coerce "\\\\?\\REL\\a") 'same)
+  (test (string->path ".") build-path (coerce "\\\\?\\REL\\a") 'up)
+  (test (string->path "\\\\?\\REL\\\\apple") build-path (coerce "\\\\?\\REL\\a") 'up (coerce "apple"))
+  (test (string->path ".") build-path (coerce "\\\\?\\REL\\a") 'up 'same)
+
+  (test (string->path "\\\\?\\REL\\..\\\\a") build-path 'up (coerce "\\\\?\\REL\\a"))
+  (test (string->path "\\\\?\\REL\\..\\\\..") build-path 'up (coerce "\\\\?\\REL\\\\.."))
+  (test (string->path "\\\\?\\REL\\..\\..") build-path 'up (coerce "\\\\?\\REL\\.."))
+  (test (string->path "\\\\?\\REL\\..\\..") build-path (coerce "\\\\?\\REL\\..") 'up)
+  (test (string->path "\\\\?\\REL\\..\\..\\..") build-path 'up (coerce "\\\\?\\REL\\..") 'up)
+  (test (string->path "\\\\?\\REL\\..\\..\\\\..") build-path 'up (coerce "\\\\?\\REL\\..") (coerce "\\\\?\\REL\\\\.."))
+  (test (string->path "\\\\?\\REL\\..\\..") build-path 'up (coerce "\\\\?\\REL\\..") (coerce "\\\\?\\REL\\\\..") 'up)
+  (test (string->path "\\\\?\\REL\\\\..\\") build-path (coerce "\\\\?\\REL\\\\..") (coerce "\\\\?\\REL\\\\..") 'up)
+  (test (string->path "\\\\?\\REL\\\\x\\") build-path (coerce "x/y") (coerce "\\\\?\\REL\\.."))
+  (test (string->path "\\\\?\\c:\\x\\") build-path (coerce "c:x/y") (coerce "\\\\?\\REL\\.."))
+
+  (test-values (list (string->path "\\\\?\\REL\\..")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\REL\\..\\a"))))
+  (test-values (list (string->path "\\\\?\\REL\\..")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\REL\\..\\\\a"))))
+  (test-values (list (string->path "\\\\?\\REL\\b\\")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\REL\\b\\a"))))
+
+  (test (string->path "\\\\?\\RED\\\\a\\") build-path (coerce "\\\\?\\RED\\a") 'same)
+  (test (string->path "\\") build-path (coerce "\\\\?\\RED\\a") 'up)
+  (test (string->path "\\\\?\\RED\\\\apple") build-path (coerce "\\\\?\\RED\\a") 'up (coerce "apple"))
+  (test (string->path "\\") build-path (coerce "\\\\?\\RED\\a") 'up 'same)
+
+  (test (string->path "\\") build-path (coerce "\\\\?\\RED\\..") 'up)
+  (test (string->path "\\\\?\\RED\\\\..\\") build-path (coerce "\\\\?\\RED\\\\..") (coerce "\\\\?\\RED\\\\..") 'up)
+  (test (string->path "\\\\?\\RED\\\\x\\y\\..") build-path (coerce "/x/y") (coerce "\\\\?\\RED\\.."))
+  (test (string->path "\\\\?\\c:\\x\\y\\..") build-path (coerce "c:x/y") (coerce "\\\\?\\RED\\.."))
+
+  (test-values (list (string->path "\\\\?\\RED\\..\\")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\RED\\..\\a"))))
+  (test-values (list (string->path "\\\\?\\RED\\..\\")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\RED\\..\\\\a"))))
+  (test-values (list (string->path "\\\\?\\RED\\b\\")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\RED\\b\\a"))))
+  (test-values (list (string->path "\\")
+                     (string->path "\\\\?\\REL\\\\..")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\RED\\.."))))
+  (test-values (list (string->path "\\")
+                     (string->path "\\\\?\\REL\\\\a")
+                     #f)
+               (lambda () (split-path (coerce "\\\\?\\RED\\a"))))
+
+  (test (string->path "\\\\?\\UNC\\f\\g") build-path (coerce "//f/g/h") (coerce "\\\\?\\REL\\.."))
+  (test (string->path "\\\\?\\UNC\\f\\g\\h\\") build-path (coerce "//f/g/h/i") (coerce "\\\\?\\REL\\.."))
+  (test (string->path "\\\\?\\UNC\\f\\g\\h\\..") build-path (coerce "//f/g/h") (coerce "\\\\?\\REL\\\\.."))
+  (test (string->path "\\\\?\\UNC\\f\\g\\h\\..") build-path (coerce "//f/g//h") (coerce "\\\\?\\REL\\\\.."))
+  (test (string->path "\\\\?\\UNC\\f\\g\\i\\x") build-path (coerce "//f/g/h/../i") (coerce "\\\\?\\REL\\x"))
+  (test (string->path "\\\\?\\UNC\\f\\g\\h\\i\\x") build-path (coerce "//f/g/../h/i") (coerce "\\\\?\\REL\\x"))
+
+  (let ([go (lambda (drive build-path simple)
+              (test (string->path (string-append "\\\\?\\" drive "f\\g\\")) 
+                    build-path (coerce "/f/g/h") (coerce "\\\\?\\REL\\.."))
+              (test (string->path (string-append "\\\\?\\" drive "f\\g\\h\\x")) 
+                    build-path (coerce "/f/g/h") (coerce "\\\\?\\REL\\x"))
+              (test (string->path (string-append "\\\\?\\" drive "f\\g\\h\\x"))
+                    build-path (coerce "//f//g/h") (coerce "\\\\?\\REL\\x"))
+              (test (string->path (string-append "\\\\?\\" drive "f\\g\\h\\x"))
+                    build-path (coerce "/f//g////h") (coerce "\\\\?\\REL\\x"))
+              (test (string->path simple) 
+                    build-path (coerce "/f//g////h") (coerce "\\\\?\\REL\\..\\..\\..\\.."))
+              (test (string->path (string-append "\\\\?\\" drive "?\\g\\h\\x")) 
+                    build-path (coerce "//?/g/h") (coerce "\\\\?\\REL\\x")))])
+    (go "RED\\\\" build-path "\\")
+    (go "C:\\" (lambda args (path->complete-path (apply build-path args) (coerce "C:"))) "C:\\"))
+    
+  ;; Allow \\?\ as a drive to add an absolute path:
+  (test (string->path "\\\\?\\c:\\b") build-path (coerce "\\\\?\\c:\\") (coerce "\\b"))
+  (test (string->path "\\\\?\\c:\\b") build-path (coerce "\\\\?\\c:\\\\") (coerce "\\b"))
+  (test (string->path "\\\\?\\c:\\b\\") build-path (coerce "\\\\?\\c:\\\\") (coerce "\\b\\"))
+  (test (string->path "\\\\?\\UNC\\goo\\bar\\b") build-path (coerce "\\\\?\\UNC\\goo\\bar") (coerce "\\b"))
+  (test (string->path "\\\\?\\\\b") build-path (coerce "\\\\?\\") (coerce "\\b"))
+  (test (string->path "\\\\?\\\\b\\") build-path (coerce "\\\\?\\") (coerce "\\b\\"))
+  (err/rt-test (build-path "\\\\?\\c:" (coerce "\\b")) exn:fail:contract?)
+  
+  ;; Don't allow path addition on bad \\?\ to change the root:
+  (test (string->path "\\\\?\\\\c") build-path (coerce "\\\\?\\") (coerce "c"))
+  (test (string->path "\\\\?\\\\UNC") build-path (coerce "\\\\?\\") (coerce "UNC"))
+  (test (string->path "\\\\?\\\\UNC\\s\\y") build-path (coerce "\\\\?\\UNC") (coerce "s/y"))
+  (test (string->path "\\\\?\\\\UNC\\s\\y") build-path (coerce "\\\\?\\UNC\\") (coerce "s/y"))
+  (test (string->path "\\\\?\\\\REL\\s\\y") build-path (coerce "\\\\?\\REL") (coerce "s/y"))
+  (test (string->path "\\\\?\\\\REL\\s\\y") build-path (coerce "\\\\?\\REL\\") (coerce "s/y"))
+  (test (string->path "\\\\?\\REL\\\\\\s\\y") build-path (coerce "\\\\?\\REL\\\\") (coerce "s/y"))
+  (test (string->path "\\\\?\\REL\\x\\\\\\z") build-path (coerce "\\\\?\\REL\\x\\\\") (coerce "z"))
+  (test (string->path "/apple\\x") build-path (coerce "//apple") (coerce "x"))
+  (test (string->path "\\\\?") build-path (coerce "\\\\") (coerce "?"))
+  (test (string->path "\\?\\") build-path (coerce "\\\\") (coerce "?\\"))
+  (test (string->path "\\?\\a") build-path (coerce "\\\\") (coerce "?") (coerce "a"))
+  (test (string->path "\\?\\a") build-path (coerce "\\\\?") (coerce "a"))
+  (test (string->path "\\?\\a\\") build-path (coerce "\\\\?") (coerce "a\\"))
+  (test (string->path "\\\\?\\\\c:") build-path (coerce "\\\\?\\") (coerce "\\\\?\\REL\\c:"))
+  (test (string->path "\\\\?\\\\c:\\") build-path (coerce "\\\\?\\") (coerce "\\\\?\\REL\\c:\\"))
+  (test (string->path "\\\\?\\\\c:\\a") build-path (coerce "\\\\?\\") (coerce "\\\\?\\REL\\c:\\a"))
+  (test (string->path "\\\\?\\\\REL\\b") build-path (coerce "\\\\?\\") (coerce "\\\\?\\REL\\REL\\b"))
+  (test (string->path "\\\\?\\\\host\\vol\\a\\") build-path (coerce "\\\\?\\") (coerce "\\\\?\\REL\\\\host\\vol\\a\\"))
+
+  ;; UNC paths can't have "?" for machine or "/" in machine part:
+  (test (list (string->path "/?/") (string->path "x")) get-base (coerce "//?/x"))
+  (test (list (string->path "\\\\?\\UNC\\a/b\\") (string->path "x")) get-base (coerce "\\\\?\\UNC\\a/b\\x"))
+
+  ;; Split path must treat \\?\ part as a root:
+  (test (list (string->path "\\\\?\\c:\\") (string->path "a")) get-base (coerce "\\\\?\\c:\\a"))
+  (test (list (string->path "\\\\?\\") (string->path "\\\\?\\REL\\\\c:")) get-base (coerce "\\\\?\\c:"))
+  (test (list #f (string->path "\\\\?\\c:\\")) get-base (coerce "\\\\?\\c:\\"))
+  (test (list #f (string->path "\\\\?\\c:\\\\")) get-base (coerce "\\\\?\\c:\\\\"))
+  (test (list (string->path "\\\\?\\c:\\") (string->path "a")) get-base (coerce "\\\\?\\c:\\\\a"))
+  (test (list #f (string->path "\\\\?\\UNC\\mach\\vol")) get-base (coerce "\\\\?\\UNC\\mach\\vol"))
+  (test (list #f (string->path "\\\\?\\UNC\\mach\\\\vol")) get-base (coerce "\\\\?\\UNC\\mach\\\\vol"))
+  (test (list #f (string->path "\\\\?\\UNC\\\\mach\\vol")) get-base (coerce "\\\\?\\UNC\\\\mach\\vol"))
+  (test (list (string->path "\\\\?\\") (string->path "c")) get-base (coerce "\\\\?\\c"))
+  (test (list (string->path "\\\\?\\UNC\\") (string->path "x")) get-base (coerce "\\\\?\\UNC\\x"))
+  (test (list (string->path "\\\\?\\") (string->path "UNC")) get-base (coerce "\\\\?\\UNC\\"))
+  (test (list #f (string->path "\\\\?\\UNC\\\\")) get-base (coerce "\\\\?\\UNC\\\\"))
+  (test (list #f (string->path "\\\\?\\xyz\\\\")) get-base (coerce "\\\\?\\xyz\\\\"))
+  (test (list (string->path "\\\\?\\c:\\a\\\\") (string->path "b")) get-base (coerce "\\\\?\\c:\\a\\\\\\b\\"))
+  (test (list #f (string->path "\\\\?\\c:\\a\\\\\\")) get-base (coerce "\\\\?\\c:\\a\\\\\\"))
+  (test (list (string->path "\\\\?\\UNC\\") (string->path "\\\\?\\REL\\\\x/y")) get-base (coerce "\\\\?\\UNC\\x/y"))
+  (test (list #f (string->path "\\\\?\\UNC\\x\\y")) get-base (coerce "\\\\?\\UNC\\x\\y"))
+  (test (list (string->path "\\\\?\\REL\\\\x\\y ") (string->path "z")) get-base (coerce "x/y /z"))
+  (test (list (string->path "\\\\?\\REL\\\\y ") (string->path "z")) get-base (coerce "x/../y /z"))
+  (test (list (string->path "\\\\?\\REL\\..\\\\y ") (string->path "z")) get-base (coerce "../y /z"))
+  (test (list (string->path "\\\\?\\c:\\y ") (string->path "z")) get-base (coerce "c:/y /z"))
+  (test (list (string->path "\\\\?\\c:\\y ") (string->path "z")) get-base (coerce "c:/../y /z"))
+  (test (list (string->path "../aux/") (string->path "z")) get-base (coerce "../aux/z"))
+  (test (list (string->path "../aux.m/") (string->path "z")) get-base (coerce "../aux.m/z"))
+  (test (list (string->path "..") (string->path "\\\\?\\REL\\\\aux.m")) get-base (coerce "../aux.m/"))
+  (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux.m")) get-base (coerce "c:/aux.m/"))
+  (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux.m.p")) get-base (coerce "c:/aux.m.p/"))
+  (test (list (string->path "c:/") (string->path "\\\\?\\REL\\\\aux:m")) get-base (coerce "c:/aux:m/"))
+  (test (list (string->path "..") (string->path "aux.m")) get-base (coerce "../aux.m"))
+  
+  ;; simplify-path leaves literal . and .. alone:
+  (test (string->path "\\\\?\\c:\\b\\.\\..\\a") simplify-path (coerce "\\\\?\\c:\\b\\.\\..\\a") #f)
+  (test (string->path "\\\\?\\c:\\B\\.\\..\\a") normal-case-path (coerce "\\\\?\\c:\\B\\.\\..\\a"))
+  (test (string->path "\\\\?\\UNC\\foo\\A") normal-case-path (coerce "\\\\?\\UNC\\foo\\A"))
+  (test (string->path "\\\\?\\RED\\..\\..") normal-case-path (coerce "\\\\?\\RED\\..\\.."))
+
+  ;; expand-path removes redundant backslashes
+  (when (eq? 'windows (system-type))
+    (test (string->path "\\\\?\\\\UNC\\x\\y") expand-path (coerce "\\\\?\\\\UNC\\x\\y"))
+    (test (string->path "\\\\?\\c:\\") expand-path (coerce "\\\\?\\c:\\\\")))
+
+  ;; expand-path removes redundant backslashes, and
+  ;; simplify-path uses expand-path under Windows:
+  (let ([go
+         (lambda (expand-path)
+           (test (string->path "c:\\") expand-path (coerce "c:"))
+           (test (string->path "C:/") expand-path (coerce "C://"))
+           (test (string->path "C:/a/") expand-path (coerce "C://a//"))
+           (test (string->path "\\\\?\\c:\\a\\.") expand-path (coerce "\\\\?\\c:\\\\a\\\\."))
+           (test (string->path "\\\\?\\c:\\a\\\\") expand-path (coerce "\\\\?\\c:\\a\\\\"))
+           (test (string->path "\\\\?\\c:\\a\\.") expand-path (coerce "\\\\?\\c:\\a\\\\."))
+           (test (string->path "\\\\?\\\\c:") expand-path (coerce "\\\\?\\c:"))
+           (test (string->path "\\\\?\\UNC\\a\\b\\.") expand-path (coerce "\\\\?\\UNC\\\\a\\b\\."))
+           (test (string->path "\\\\?\\UNC\\a\\b\\.") expand-path (coerce "\\\\?\\UNC\\\\a\\b\\\\."))
+           (test (string->path "\\\\?\\RED\\\\..") expand-path (coerce "\\\\?\\RED\\.."))
+           (test (string->path "\\\\?\\") expand-path (coerce "\\\\?\\\\")))])
+    (when (eq? 'windows (system-type))
+      (go expand-path)
+      (go simplify-path))
+    (go (lambda (p) (simplify-path p #f))))
+
+  (test (bytes->path #"..") simplify-path (coerce "\\\\?\\REL\\..") #F)
+  (test (bytes->path #"..") simplify-path (coerce "\\\\?\\REL\\..\\") #F)
+  (when (eq? 'windows (system-type))
+    (test (bytes->path #"\\\\foo\\bar\\") expand-path (coerce "\\\\foo\\bar\\")))
+  (test (bytes->path #"\\\\foo\\bar") simplify-path (coerce "\\\\foo\\bar\\") #f)
+  (test (bytes->path #"\\\\foo\\bar") simplify-path (coerce "\\\\?\\UNC\\foo\\bar") #f)
+  (test (bytes->path #"\\\\foo\\bar") simplify-path (coerce "\\\\?\\UNC\\foo\\bar\\") #f)
+  (test (bytes->path #"\\\\?\\UNC\\foo\\bar\\..") simplify-path (coerce "\\\\?\\UNC\\foo\\bar\\..") #f)
+  (test (bytes->path #"\\\\?\\UNC\\foo\\bar\\..\\") simplify-path (coerce "\\\\?\\UNC\\foo\\bar\\..\\") #f)
+  (test (bytes->path #"a") simplify-path (coerce "\\\\?\\REL\\a") #f)
+  (test (bytes->path #"a") simplify-path (coerce "\\\\?\\REL\\\\a") #f)
+  (test (bytes->path #"a\\") simplify-path (coerce "\\\\?\\REL\\\\a\\") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\a/") simplify-path (coerce "\\\\?\\REL\\\\a/") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\..") simplify-path (coerce "\\\\?\\REL\\\\..") #F)
+  (test (bytes->path #"\\\\?\\REL\\\\..\\") simplify-path (coerce "\\\\?\\REL\\\\..\\") #F)
+  (test (bytes->path #"a \\b") simplify-path (coerce "\\\\?\\REL\\\\a \\b") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\aux.bad\\b") simplify-path (coerce "\\\\?\\REL\\aux.bad\\b") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\a\\b  ") simplify-path (coerce "\\\\?\\REL\\a\\b  ") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\.\\b") simplify-path (coerce "\\\\?\\REL\\.\\b") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\.") simplify-path (coerce "\\\\?\\REL\\.") #F)
+  (test (bytes->path #"\\\\?\\REL\\\\:\\b") simplify-path (coerce "\\\\?\\REL\\:\\b") #f)
+  (test (bytes->path #"\\\\?\\REL\\\\:") simplify-path (coerce "\\\\?\\REL\\:") #F)
+  (test (bytes->path #"\\\\?\\\\REL") simplify-path (coerce "\\\\?\\REL") #F)
+  (test (bytes->path #"\\\\?\\\\REL") simplify-path (coerce "\\\\?\\\\REL") #F)
+  (test (bytes->path #"C:\\a\\b") simplify-path (coerce "\\\\?\\C:\\a\\b") #f)
+  (test (bytes->path #"C:\\a") simplify-path (coerce "\\\\?\\C:\\a") #f)
+  (test (bytes->path #"\\\\?\\C:\\a ") simplify-path (coerce "\\\\?\\C:\\a ") #f)
+  (test (bytes->path #"\\\\?\\\\C:a\\b") simplify-path (coerce "\\\\?\\C:a\\b") #f)
+  (test (bytes->path #"\\\\?\\\\C:a\\b") simplify-path (coerce "\\\\?\\\\C:a\\b") #f)
+  (test (bytes->path #"\\\\?\\\\C:") simplify-path (coerce "\\\\?\\C:") #f)
+  (test (bytes->path #"\\\\?\\\\C:") simplify-path (coerce "\\\\?\\\\C:") #f)
+  (test (bytes->path #"\\\\?\\\\a\\y") simplify-path (coerce "\\\\?\\a\\y") #f)
+  (test (bytes->path #"\\\\?\\\\a\\y") simplify-path (coerce "\\\\?\\\\a\\y") #f)
+  (test (bytes->path #"\\\\?\\REL\\a\\y\\\\") simplify-path (coerce "\\\\?\\REL\\a\\y\\\\") #f)
+  (test (bytes->path #"\\\\?\\REL\\a\\\\\\y") simplify-path (coerce "\\\\?\\REL\\a\\\\\\y") #f)
+  (test (bytes->path #"\\a") simplify-path (coerce "\\\\?\\RED\\a") #f)
+  (test (bytes->path #"\\a") simplify-path (coerce "\\\\?\\RED\\\\a") #f)
+  (test (bytes->path #"\\a\\b") simplify-path (coerce "\\\\?\\RED\\\\a\\\\b") #f))
+
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; ~ paths and other subtleties in Unix
 
-(test (and (memq (system-type) '(unix macosx)) #t) absolute-path? "~")
-(when (absolute-path? "~")
-  (test #t relative-path? "./~")
-  (test (bytes->path #"./~") bytes->path-element #"~")
-  (test #"~" path-element->bytes (bytes->path #"./~"))
-  (test #"~" path-element->bytes (bytes->path #"./~/"))
-  (test #"a" path-element->bytes (bytes->path #"a////////////"))
-  (test (bytes->path #"./~me") bytes->path-element #"~me")
-  (test #"~me" path-element->bytes (bytes->path #"./~me"))
-  (err/rt-test (path-element->bytes (bytes->path #"x/y")))
-  (err/rt-test (path-element->bytes (bytes->path #"x/~me")))
-  (err/rt-test (path-element->bytes (bytes->path #"/me")))
-  (err/rt-test (path-element->bytes (bytes->path #"/")))
-  (err/rt-test (bytes->path-element #"./~"))
-  (err/rt-test (bytes->path-element #"x/y"))
-  (err/rt-test (bytes->path-element #"/x"))
-  (err/rt-test (bytes->path-element #"/"))
-  (test (bytes->path #"~") simplify-path (bytes->path #"~"))
-  (test (bytes->path #"~") simplify-path (bytes->path #"~/"))
-  (test (bytes->path #"~") simplify-path (bytes->path #"~/."))
-  (test (bytes->path #"./~") simplify-path (bytes->path #"./~"))
-  (test (bytes->path #"./~/") simplify-path (bytes->path #"./~/"))
-  (test (bytes->path #"~/../..") simplify-path (bytes->path #"~/../..") #f)
-  (test (bytes->path #"~/..") simplify-path (bytes->path #"~/../x/..") #f)
-  (test (bytes->path #"..") simplify-path (bytes->path #"../x/..") #f)
-  (test (bytes->path #"x/") simplify-path (bytes->path #"x/~/..") #f)
-  (test (bytes->path #".") simplify-path (bytes->path #"./") #f)
-  (test (bytes->path #".") simplify-path (bytes->path #".//") #f)
-  (test (bytes->path #"..") simplify-path (bytes->path #"../") #f)
-  (test (bytes->path #"..") simplify-path (bytes->path #"..//") #f)
-  (test (bytes->path #"..") simplify-path (bytes->path #"..//./") #f)
-  (test (bytes->path #"x/") path->directory-path (bytes->path #"x"))
-  (test (bytes->path #"x/") path->directory-path (bytes->path #"x/"))
-  (test (bytes->path #"x/.") path->directory-path (bytes->path #"x/."))
-  (test (bytes->path #"x/./") path->directory-path (bytes->path #"x/./"))
-  (test (bytes->path #"x/..") path->directory-path (bytes->path #"x/.."))
-  (test (bytes->path #"x/../") path->directory-path (bytes->path #"x/../"))
-  (test (bytes->path #".") path->directory-path (bytes->path #"."))
-  (test (bytes->path #"./") path->directory-path (bytes->path #"./"))
-  (test (bytes->path #"..") path->directory-path (bytes->path #".."))
-  (test (bytes->path #"../") path->directory-path (bytes->path #"../"))
-  (test (bytes->path #"~") path->directory-path (bytes->path #"~"))
-  (test (bytes->path #"~me") path->directory-path (bytes->path #"~me"))
-  (test (bytes->path #"~/") path->directory-path (bytes->path #"~/"))
-  (test (bytes->path #"~me/") path->directory-path (bytes->path #"~me/"))
-  (test (bytes->path #"./~/") path->directory-path (bytes->path #"./~"))
-  (test-values (list #f (bytes->path #"~me") #t) (lambda () (split-path (bytes->path #"~me"))))
-  (test-values (list #f (bytes->path #"~me") #t) (lambda () (split-path (bytes->path #"~me/"))))
-  (test-values (list 'relative (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"./~me"))))
-  (test-values (list 'relative (bytes->path #"./~me") #t) (lambda () (split-path (bytes->path #"./~me/"))))
-  (test-values (list (bytes->path #"./.") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"././~me"))))
-  (test-values (list 'relative (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #".//~me"))))
-  (test-values (list (bytes->path #"y/x/") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"y/x/~me"))))
-  (test-values (list (bytes->path #"y/x/") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"y//x//~me"))))
-  (test-values (list (bytes->path #"y/x/.") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"y/x/./~me"))))
-  (test-values (list (bytes->path #"x/") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"x/~me"))))
-  (test-values (list (bytes->path #"x/") (bytes->path #"./~me") #t) (lambda () (split-path (bytes->path #"x/~me/"))))
-  (test-values (list (bytes->path #"x/.") (bytes->path #"y") #f) (lambda () (split-path (bytes->path #"x/./y"))))
-  (test-values (list (bytes->path #"x/..") (bytes->path #"y") #f) (lambda () (split-path (bytes->path #"x/../y"))))
-  (test-values (list (bytes->path #"~me") (bytes->path #"y") #f) (lambda () (split-path (bytes->path #"~me/y"))))
-  (test-values (list (bytes->path #"~me/y/") (bytes->path #"z") #f) (lambda () (split-path (bytes->path #"~me/y/z"))))
-  (test (bytes->path #"/home/mflatt/~") build-path (bytes->path #"/home/mflatt") (bytes->path #"./~"))
-  (test (bytes->path #"/home/mflatt/././~") build-path (bytes->path #"/home/mflatt") (bytes->path #"././~"))
-  (test (bytes->path #"./~") build-path (bytes->path #"./~"))
-  (let ([dir "tmp79"])
-    (unless (directory-exists? dir)
-      (make-directory dir))
-    (close-output-port (open-output-file "tmp79/~me" 'replace))
-    (test (list (bytes->path #"./~me")) directory-list dir)
-    (delete-file (build-path "tmp79" (bytes->path #"./~me")))
-    (delete-directory dir))
-  (void))
+(test (and (memq (system-path-convention-type) '(unix)) #t) absolute-path? "~")
+(test #t absolute-path? (bytes->path #"~" 'unix))
+(test #f absolute-path? (bytes->path #"~" 'windows))
+
+(define (test-~-paths kind)
+  (let* ([use-fs? (eq? kind (system-path-convention-type))]
+         [bytes->path (if use-fs?
+                          bytes->path
+                          (lambda (s) (bytes->path s kind)))]
+         
+         [bytes->path-element (if use-fs?
+                                  bytes->path-element
+                                  (lambda (s) (bytes->path-element s kind)))])
+    (test #t relative-path? (bytes->path #"./~"))
+    (test (bytes->path #"./~") bytes->path-element #"~")
+    (test #"~" path-element->bytes (bytes->path #"./~"))
+    (test #"~" path-element->bytes (bytes->path #"./~/"))
+    (test #"a" path-element->bytes (bytes->path #"a////////////"))
+    (test (bytes->path #"./~me") bytes->path-element #"~me")
+    (test #"~me" path-element->bytes (bytes->path #"./~me"))
+    (err/rt-test (path-element->bytes (bytes->path #"x/y")))
+    (err/rt-test (path-element->bytes (bytes->path #"x/~me")))
+    (err/rt-test (path-element->bytes (bytes->path #"/me")))
+    (err/rt-test (path-element->bytes (bytes->path #"/")))
+    (err/rt-test (bytes->path-element #"./~"))
+    (err/rt-test (bytes->path-element #"x/y"))
+    (err/rt-test (bytes->path-element #"/x"))
+    (err/rt-test (bytes->path-element #"/"))
+    (test (bytes->path #"~") simplify-path (bytes->path #"~") use-fs?)
+    (test (bytes->path #"~") simplify-path (bytes->path #"~/") use-fs?)
+    (test (bytes->path #"~") simplify-path (bytes->path #"~/.") use-fs?)
+    (test (bytes->path #"./~") simplify-path (bytes->path #"./~") use-fs?)
+    (test (bytes->path #"./~/") simplify-path (bytes->path #"./~/") use-fs?)
+    (test (bytes->path #"~/../..") simplify-path (bytes->path #"~/../..") #f)
+    (test (bytes->path #"~/..") simplify-path (bytes->path #"~/../x/..") #f)
+    (test (bytes->path #"..") simplify-path (bytes->path #"../x/..") #f)
+    (test (bytes->path #"x/") simplify-path (bytes->path #"x/~/..") #f)
+    (test (bytes->path #".") simplify-path (bytes->path #"./") #f)
+    (test (bytes->path #".") simplify-path (bytes->path #".//") #f)
+    (test (bytes->path #"..") simplify-path (bytes->path #"../") #f)
+    (test (bytes->path #"..") simplify-path (bytes->path #"..//") #f)
+    (test (bytes->path #"..") simplify-path (bytes->path #"..//./") #f)
+    (test (bytes->path #"x/") path->directory-path (bytes->path #"x"))
+    (test (bytes->path #"x/") path->directory-path (bytes->path #"x/"))
+    (test (bytes->path #"x/.") path->directory-path (bytes->path #"x/."))
+    (test (bytes->path #"x/./") path->directory-path (bytes->path #"x/./"))
+    (test (bytes->path #"x/..") path->directory-path (bytes->path #"x/.."))
+    (test (bytes->path #"x/../") path->directory-path (bytes->path #"x/../"))
+    (test (bytes->path #".") path->directory-path (bytes->path #"."))
+    (test (bytes->path #"./") path->directory-path (bytes->path #"./"))
+    (test (bytes->path #"..") path->directory-path (bytes->path #".."))
+    (test (bytes->path #"../") path->directory-path (bytes->path #"../"))
+    (test (bytes->path #"~") path->directory-path (bytes->path #"~"))
+    (test (bytes->path #"~me") path->directory-path (bytes->path #"~me"))
+    (test (bytes->path #"~/") path->directory-path (bytes->path #"~/"))
+    (test (bytes->path #"~me/") path->directory-path (bytes->path #"~me/"))
+    (test (bytes->path #"./~/") path->directory-path (bytes->path #"./~"))
+    (test-values (list #f (bytes->path #"~me") #t) (lambda () (split-path (bytes->path #"~me"))))
+    (test-values (list #f (bytes->path #"~me") #t) (lambda () (split-path (bytes->path #"~me/"))))
+    (test-values (list 'relative (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"./~me"))))
+    (test-values (list 'relative (bytes->path #"./~me") #t) (lambda () (split-path (bytes->path #"./~me/"))))
+    (test-values (list (bytes->path #"./.") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"././~me"))))
+    (test-values (list 'relative (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #".//~me"))))
+    (test-values (list (bytes->path #"y/x/") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"y/x/~me"))))
+    (test-values (list (bytes->path #"y/x/") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"y//x//~me"))))
+    (test-values (list (bytes->path #"y/x/.") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"y/x/./~me"))))
+    (test-values (list (bytes->path #"x/") (bytes->path #"./~me") #f) (lambda () (split-path (bytes->path #"x/~me"))))
+    (test-values (list (bytes->path #"x/") (bytes->path #"./~me") #t) (lambda () (split-path (bytes->path #"x/~me/"))))
+    (test-values (list (bytes->path #"x/.") (bytes->path #"y") #f) (lambda () (split-path (bytes->path #"x/./y"))))
+    (test-values (list (bytes->path #"x/..") (bytes->path #"y") #f) (lambda () (split-path (bytes->path #"x/../y"))))
+    (test-values (list (bytes->path #"~me") (bytes->path #"y") #f) (lambda () (split-path (bytes->path #"~me/y"))))
+    (test-values (list (bytes->path #"~me/y/") (bytes->path #"z") #f) (lambda () (split-path (bytes->path #"~me/y/z"))))
+    (test (bytes->path #"/home/mflatt/~") build-path (bytes->path #"/home/mflatt") (bytes->path #"./~"))
+    (test (bytes->path #"/home/mflatt/././~") build-path (bytes->path #"/home/mflatt") (bytes->path #"././~"))
+    (test (bytes->path #"./~") build-path (bytes->path #"./~"))
+    (when use-fs?
+      (let ([dir "tmp79"])
+        (unless (directory-exists? dir)
+          (make-directory dir))
+        (close-output-port (open-output-file "tmp79/~me" 'replace))
+        (test (list (bytes->path #"./~me")) directory-list dir)
+        (delete-file (build-path "tmp79" (bytes->path #"./~me")))
+        (delete-directory dir)))
+    (void)))
+
+(test-~-paths 'unix)
 
 
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/collects/tests/mzscheme/sync.ss b/collects/tests/mzscheme/sync.ss
index 09a2f1a053..f911c9fbef 100644
--- a/collects/tests/mzscheme/sync.ss
+++ b/collects/tests/mzscheme/sync.ss
@@ -20,7 +20,7 @@
   (test p sync p)
   (test s sync s)
   (test #f sync/timeout 0 p)
-  (thread (lambda () (sleep SYNC-SLEEP-DELAY) (semaphore-post s)))
+  (thread (lambda () (sync (system-idle-evt)) (semaphore-post s)))
   (test p sync p)
   (test p sync p)
   (test s sync s)
@@ -34,7 +34,7 @@
   (test 7 channel-get ch)
   (test #f channel-try-get ch)
   (thread (lambda () (channel-put ch 9)))
-  (sleep SYNC-SLEEP-DELAY)
+  (sync (system-idle-evt))
   (test 9 channel-try-get ch)
   (test #f channel-try-get ch))
 
@@ -50,19 +50,19 @@
 (let ([c (make-channel)]
       [v 'nope])
   (test #f sync/timeout 0 c)
-  (thread (lambda () (sleep SYNC-SLEEP-DELAY) (set! v (channel-get c))))
+  (thread (lambda () (sync (system-idle-evt)) (set! v (channel-get c))))
   (test (void) channel-put c 10)
-  (sleep)
+  (sync (system-idle-evt))
   (test 10 'thread-v v)
-  (thread (lambda () (sleep SYNC-SLEEP-DELAY) (channel-put c 11)))
+  (thread (lambda () (sync (system-idle-evt)) (channel-put c 11)))
   (test #f sync/timeout 0 c)
   (test 11 sync c)
   (let ([p (channel-put-evt c 45)])
-    (thread (lambda () (sleep SYNC-SLEEP-DELAY) (set! v (sync c))))
+    (thread (lambda () (sync (system-idle-evt)) (set! v (sync c))))
     (test #f sync/timeout 0 p)
     (test p sync p)
     (test #f sync/timeout 0 p)
-    (sleep)
+    (sync (system-idle-evt))
     (test 45 'thread-v v))
   ;;;;; Make sure break/kill before action => break/kill only
   ;; get:
@@ -70,11 +70,11 @@
 	       (let ([t (thread (lambda ()
 				  (set! v (channel-get c))))])
 		 (test #t thread-running? t)
-		 (sleep)
+		 (sync (system-idle-evt))
 		 (test #t thread-running? t)
 		 (test (void) break-thread t)
 		 (test #f sync/timeout 0 (channel-put-evt c 32))
-		 (sleep)
+                 (sync (system-idle-evt))
 		 (test #f thread-running? t)
 		 (test 45 'old-v v)))])
     (try break-thread)
@@ -83,18 +83,18 @@
   (let ([try (lambda (break-thread)
 	       (let ([t (thread (lambda () (channel-put c 17)))])
 		 (test #t thread-running? t)
-		 (sleep)
+		 (sync (system-idle-evt))
 		 (test #t thread-running? t)
 		 (test (void) break-thread t)
 		 (test #f sync/timeout 0 c)
-		 (sleep)
+		 (sync (system-idle-evt))
 		 (test #f thread-running? t)))])
     (try break-thread)
     (try kill-thread))
   ;; put in main thread:
   (let ([t (current-thread)])
     (thread (lambda () 
-	      (sleep SYNC-SLEEP-DELAY) 
+	      (sync (system-idle-evt))
 	      (break-thread t) 
 	      (set! v (channel-get c)))))
   (test 77
@@ -108,7 +108,7 @@
   ;; get in main thread:
   (let ([t (current-thread)])
     (thread (lambda () 
-	      (sleep SYNC-SLEEP-DELAY) 
+	      (sync (system-idle-evt))
 	      (break-thread t) 
 	      (channel-put c 66))))
   (test 99
@@ -215,8 +215,8 @@
 	  (make-semaphore) (make-semaphore) (make-semaphore) (make-semaphore) 
 	  (let ([sema (make-semaphore 1)])
 	    (wrap-evt sema (lambda (x)
-					  (test sema values x)
-					  77)))))))
+                             (test sema values x)
+                             77)))))))
 
 ;; More alarms:
 (let ([make-delay
@@ -250,14 +250,14 @@
 (test 18 'sync
       (let ([n 17]
 	    [s (make-semaphore)])
-	(thread (lambda () (sleep SYNC-SLEEP-DELAY) (semaphore-post s)))
+	(thread (lambda () (sync (system-idle-evt)) (semaphore-post s)))
 	(sync 
-			      (wrap-evt 
-			       s 
-			       (lambda (sema) (set! n (add1 n)) n))
-			      (wrap-evt 
-			       s 
-			       (lambda (sema) (set! n (add1 n)) n)))))
+         (wrap-evt 
+          s 
+          (lambda (sema) (set! n (add1 n)) n))
+         (wrap-evt 
+          s 
+          (lambda (sema) (set! n (add1 n)) n)))))
 
 (let ([c (make-channel)])
   (thread (lambda () (channel-put c 76)))
@@ -666,12 +666,12 @@
     (test t sync/timeout 0 s)
     (test t sync/timeout 0 r)
     (let* ([s (thread-suspend-evt t)])
-      (thread (lambda () (sleep SYNC-SLEEP-DELAY) (thread-suspend t)))
+      (thread (lambda () (sync (system-idle-evt)) (thread-suspend t)))
       (test #f sync/timeout 0 s)
       (test t sync s)
       (let* ([r (thread-resume-evt t)]
 	     [d (thread-dead-evt t)])
-	(thread (lambda () (sleep SYNC-SLEEP-DELAY) (thread-resume t)))
+	(thread (lambda () (sync (system-idle-evt)) (thread-resume t)))
 	(test #f sync/timeout 0 r)
 	(test t sync r)
 
diff --git a/collects/tests/mzscheme/thread.ss b/collects/tests/mzscheme/thread.ss
index 483853cff1..d9095836ae 100644
--- a/collects/tests/mzscheme/thread.ss
+++ b/collects/tests/mzscheme/thread.ss
@@ -221,7 +221,7 @@
     (let* ([hit? #f]
 	   [t (parameterize ([current-custodian (make-custodian)])
 		(thread (lambda () (thunk) (set! hit? #t))))])
-      (sleep SLEEP-TIME)
+      (sync (system-idle-evt))
       (begin0 (test block? 'nondeterministic-block-test (not hit?))
 	      (kill-thread t)))))
 
@@ -265,7 +265,7 @@
 			  (with-handlers ([exn:break? (lambda (x) (semaphore-post s2))])
 			    (semaphore-wait (make-semaphore 0)))))])
 	(semaphore-wait s1)
-	(sleep SLEEP-TIME)
+	(sync (system-idle-evt))
 	(break-thread t)
 	(semaphore-wait s2)
 	'ok))
@@ -370,7 +370,7 @@
 		(lambda ()
 		  (semaphore-wait s)
 		  (set! l (cons who l)))))]
-       [pause (lambda () (sleep 0.01))])
+       [pause (lambda () (sync (system-idle-evt)))])
   (wait 0) (pause)
   (wait 1) (pause)
   (wait 2)
@@ -701,7 +701,7 @@
   (let ([t2 (thread (lambda () 
 		      (thread-suspend (current-thread))
 		      (set! v 99)))])
-    (sleep SLEEP-TIME)
+    (sync (system-idle-evt))
     (test #f thread-running? t2)
     (test #f thread-dead? t2)
     (thread-resume t2)
@@ -722,7 +722,7 @@
     (test #f thread-dead? t2)
     (test #f thread-running? t2)
     (semaphore-post s)
-    (sleep SLEEP-TIME)
+    (sync (system-idle-evt))
     (test 17 values v)
     (thread-resume t2)
     (thread-wait t2)