sparse: make path absoluteness checks cross-platform

Summary: Let's be friendlier to our friends on Windows.

Test Plan: rt

Reviewers: mjpieters, #fbhgext

Differential Revision: https://phab.mercurial-scm.org/D194

hgext3rd/sparse.py

@@ -758,10 +758,9 @@ def _config(ui, repo, pats, opts, include=False, exclude=False, reset=False,
                 newexclude = set(oldexclude)
                 newprofiles = set(oldprofiles)
 
-            if any(pat.startswith('/') for pat in pats):
-                err = _('paths cannot start with /')
-                hint = _('do not use absolute paths')
-                raise error.Abort(err, hint=hint)
+            if any(os.path.isabs(pat) for pat in pats):
+                err = _('paths cannot be absolute')
+                raise error.Abort(err)
 
             if (not ui.configbool('sparse', 'includereporootpaths', False)
                 and (include or exclude)):

tests/test-sparse.t

@@ -28,14 +28,12 @@ Verify basic --include
 Absolute paths outside the repo should just be rejected
 
   $ hg sparse --include /foo/bar
-  abort: paths cannot start with /
-  (do not use absolute paths)
+  abort: paths cannot be absolute
   [255]
   $ hg sparse --include '$TESTTMP/myrepo/hide'
 
   $ hg sparse --include '/root'
-  abort: paths cannot start with /
-  (do not use absolute paths)
+  abort: paths cannot be absolute
   [255]
 
 Repo root-relaive vs. cwd-relative includes