path-components-safe: refactoring.

* stdlib/path-test.tl (path-components-safe): Simplify code;
forget trying to do anything on Windows: just return true.

* txr.1: Document that path-components-safe is useless
on Windows.

1 files changed, 37 insertions, 55 deletions

diff --git a/stdlib/path-test.tl b/stdlib/path-test.tl
index 31a4d4be..5f28b352 100644
--- a/stdlib/path-test.tl
+++ b/stdlib/path-test.tl
@@ -169,61 +169,43 @@
          (zerop st.uid))))
 
 (defun path-components-safe (path)
-  (let* ((comps (spl path-sep-chars path))
-         (start "/"))
-    (iflet ((head (car comps)))
-      (and
-        (if-native-windows
-          (match-case head
-            (@(or "" `@{vol #/[A-Za-z]+:/}`)
-              (set start `@head`
-                   comps (cdr comps))
-              (path-private-to-me-p start))
-            (`@{vol #/A-Za-z]+:/}@name`
-              (set start `@vol@name`
-                   comps (cdr comps))
-              (and (path-private-to-me-p `@vol`)
-                   (path-private-to-me-p start)))
-            (@else
-              (set start ".")
-              (let ((st (stat start)))
-                (or (path-private-to-me-p st)
-                    (path-safe-sticky-dir st)))))
-          (cond
-            ((empty head)
-              (set start "/"
-                   comps (cdr comps))
-              (path-private-to-me-p "/"))
-            (t
-              (set start ".")
-              (let ((st (stat start)))
-                (or (path-private-to-me-p st)
-                    (path-safe-sticky-dir st))))))
-      (for ((ok t) (count 0) next (orig-start start))
-           ((and ok (set next (pop comps))) ok)
-           ()
-        (let* ((nxpath (path-cat start next))
-               (st (lstat nxpath)))
-          (cond
-            ((eql (logand st.mode s-ifmt) s-iflnk)
-             (if (> (inc count) 16)
-               (throwf 'file-error "~a: too many symbolic links"
-                       'path-components-safe))
-             (if (or (zerop st.uid)
-                     (eql st.uid (geteuid)))
-               (let* ((target (readlink nxpath))
-                      (tcomps (spl path-sep-chars target)))
-                 (set comps (nconc tcomps comps))
-                 (when (abs-path-p target)
-                   (set start "/")
-                   (if (nequal orig-start "/")
-                     (set ok (path-private-to-me-p "/")
-                          orig-start nil))))
-               (set ok nil)))
-            ((or (path-private-to-me-p st)
-                 (path-safe-sticky-dir st))
-             (set start nxpath))
-            (t (zap ok)))))))))
+  (if-native-windows
+    t
+    (let* ((comps (spl path-sep-chars path))
+           (head (car comps))
+           (start "/"))
+      (if (empty head)
+        (set comps (cdr comps))
+        (set start "."))
+      (if (let ((st (stat start)))
+            (or (path-private-to-me-p st)
+                (if (nequal start "/")
+                  (path-safe-sticky-dir st))))
+        (for ((ok t) (count 0) next (orig-start start))
+             ((and ok (set next (pop comps))) ok)
+             ()
+          (let* ((nxpath (path-cat start next))
+                 (st (lstat nxpath)))
+            (cond
+              ((eql (logand st.mode s-ifmt) s-iflnk)
+               (if (> (inc count) 16)
+                 (throwf 'file-error "~a: too many symbolic links"
+                         'path-components-safe))
+               (if (or (zerop st.uid)
+                       (eql st.uid (geteuid)))
+                 (let* ((target (readlink nxpath))
+                        (tcomps (spl path-sep-chars target)))
+                   (set comps (nconc tcomps comps))
+                   (when (abs-path-p target)
+                     (set start "/")
+                     (if (nequal orig-start "/")
+                       (set ok (path-private-to-me-p "/")
+                            orig-start nil))))
+                 (set ok nil)))
+              ((or (path-private-to-me-p st)
+                   (path-safe-sticky-dir st))
+               (set start nxpath))
+              (t (zap ok)))))))))
 
 (defmacro sys:path-examine ((sym statfun path) . body)
   ^[sys:do-path-test ,statfun ,path