# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 1167444271 21600
# Node ID 315d47991fd432d52cb0df2a5d93aaf66459d5d9
# Parent  3f0ba82c103f1c19ce239c3be013b2a7b8d7c8bc
symlinks: check whether a filesystem supports symlinks

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -713,6 +713,18 @@ def execfunc(path, fallback):
         return lambda x: is_exec(os.path.join(path, x))
     return fallback
 
+def checksymlink(path):
+    """check whether the given path is on a symlink-capable filesystem"""
+    # mktemp is not racy because symlink creation will fail if the
+    # file already exists
+    name = tempfile.mktemp(dir=path)
+    try:
+        os.symlink(".", name)
+        os.unlink(name)
+        return True
+    except OSError:
+        return False
+
 # Platform specific variants
 if os.name == 'nt':
     import msvcrt