convert: fix svn file:// URL generation under Windows

hgext/convert/subversion.py

@@ -720,14 +720,19 b' class svn_sink(converter_sink, commandli'
             self.wc = path
             self.run0('update')
         else:
+            wcpath = os.path.join(os.getcwd(), os.path.basename(path) + '-wc')
+
             if os.path.isdir(os.path.dirname(path)):
                 if not os.path.exists(os.path.join(path, 'db', 'fs-type')):
                     ui.status(_('initializing svn repo %r\n') %
                               os.path.basename(path))
                     commandline(ui, 'svnadmin').run0('create', path)
                     created = path
+                path = path.replace('\\', '/')
+                if not path.startswith('/'):
+                    path = '/' + path
                 path = 'file://' + path
-            wcpath = os.path.join(os.getcwd(), os.path.basename(path) + '-wc')
+            
             ui.status(_('initializing svn wc %r\n') % os.path.basename(wcpath))
             self.run0('checkout', path, wcpath)