clone: directory names take precedence over symbolic names

If source matches both a directory name and a symbolic
name to repo, the directory will be taken.

mercurial/commands.py

@@ -614,7 +614,8 b' def clone(ui, source, dest=None, **opts)'
         ui.setconfig("ui", "remotecmd", opts['remotecmd'])
 
     d = Dircleanup(dest)
-    source = ui.expandpath(source)
+    if not os.path.exists(source):
+        source = ui.expandpath(source)
     abspath = source
     other = hg.repository(ui, source)