[tui] set attribute '_walker' to RepoViewer

# HG changeset patch
# User Takumi IINO <trot.thunder@gmail.com>
# Date 1339508723 -32400
# Node ID a537fbaebb9fc70658ae959ce9ae8f6dc04aeafa
# Parent  b3480d01ad48230487bcaa6a0c00afb1cf5ecdd8
[tui] set attribute '_walker' to RepoViewer

Press 'r', get a stack trace.

Traceback (most recent call last):
  File "/usr/bin/hgview", line 33, in <module>
    main()
  File "/usr/lib/python2.6/site-packages/hgviewlib/application.py", line 192, in main
    sys.exit(start(repo, opts, args, parser.error))
  File "/usr/lib/python2.6/site-packages/hgviewlib/application.py", line 143, in start
    return app.exec_()
  File "/usr/lib/python2.6/site-packages/hgviewlib/curses/application.py", line 87, in exec_
    out = self.mainloop.run()
  File "/usr/lib/python2.6/site-packages/urwid/main_loop.py", line 274, in run
    self.screen.run_wrapper(self._run)
  File "/usr/lib/python2.6/site-packages/urwid/raw_display.py", line 237, in run_wrapper
    return fn()
  File "/usr/lib/python2.6/site-packages/urwid/main_loop.py", line 307, in _run
    self.event_loop.run()
  File "/usr/lib/python2.6/site-packages/urwid/main_loop.py", line 682, in run
    self._loop()
  File "/usr/lib/python2.6/site-packages/urwid/main_loop.py", line 720, in _loop
    self._watch_files[fd]()
  File "/usr/lib/python2.6/site-packages/urwid/main_loop.py", line 358, in _update
    self.process_input(keys)
  File "/usr/lib/python2.6/site-packages/urwid/main_loop.py", line 447, in process_input
    k = self._topmost_widget.keypress(self.screen_size, k)
  File "/usr/lib/python2.6/site-packages/hgviewlib/curses/mainframe.py", line 152, in keypress
    emit_command(hg_command_map[key][1:])
  File "/usr/lib/python2.6/site-packages/hgviewlib/curses/utils.py", line 184, in emit
    result |= bool(data.func(*ags, **kws))
  File "/usr/lib/python2.6/site-packages/hgviewlib/curses/hgrepoviewer.py", line 331, in refresh
    self._walker.setRepo()
AttributeError: 'RepoViewer' object has no attribute '_walker'

diff --git a/hgviewlib/curses/hgrepoviewer.py b/hgviewlib/curses/hgrepoviewer.py
--- a/hgviewlib/curses/hgrepoviewer.py
+++ b/hgviewlib/curses/hgrepoviewer.py
@@ -290,9 +290,9 @@
         self._show_context = 0 # O:hide, 1:half, 2:maximized
         self.refreshing = False # flag to now if the repo is refreshing

-        walker = HgRepoListWalker(repo)
-        self.graphlog = GraphlogViewer(walker=walker)
-        self.context = ContextViewer(walker=walker)
+        self._walker = HgRepoListWalker(repo)
+        self.graphlog = GraphlogViewer(walker=self._walker)
+        self.context = ContextViewer(walker=self._walker)

         widget_list = [('weight', 1 - self.CONTEXT_SIZE, self.graphlog),]