TypeError raised when viewing mercurial changeset

[Jun Omae]

I encountered the following error while porting mercurial plugin to Python 3:

Traceback (most recent call last):
  File "/vol/src/tracdev/git/trac/web/main.py", line 610, in dispatch_request
    dispatcher.dispatch(req)
  File "/vol/src/tracdev/git/trac/web/main.py", line 302, in dispatch
    raise e
  File "/vol/src/tracdev/git/trac/web/main.py", line 248, in dispatch
    resp = chosen_handler.process_request(req)
  File "/vol/src/tracdev/git/trac/versioncontrol/web_ui/changeset.py", line 349, in process_request
    self._render_html(req, repos, chgset, restricted, data)
  File "/vol/src/tracdev/git/trac/versioncontrol/web_ui/changeset.py", line 424, in _render_html
    data['properties'] = browser.render_properties('revprop', context,
  File "/vol/src/tracdev/git/trac/versioncontrol/web_ui/browser.py", line 761, in render_properties
    [self.render_property(name, mode, context, props)
  File "/vol/src/tracdev/git/trac/versioncontrol/web_ui/browser.py", line 761, in <listcomp>
    [self.render_property(name, mode, context, props)
  File "/vol/src/tracdev/git/trac/versioncontrol/web_ui/browser.py", line 774, in render_property
    candidates.sort(reverse=True)
TypeError: '<' not supported between instances of 'DefaultPropertyRenderer' and 'HgDefaultPropertyRenderer'

Fix:

trac/versioncontrol/web_ui/browser.py

@@ -770 +770 @@
             quality = renderer.match_property(name, mode)
             if quality > 0:
                 candidates.append((quality, renderer))
-        candidates.sort(reverse=True)
+        candidates.sort(reverse=True, key=lambda c: c[0])
         for (quality, renderer) in candidates:
             try:
                 rendered = renderer.render_property(name, mode, context, props)

Work around in mercurial plugin:

     def match_property(self, name, mode):
-       return name.startswith('hg-') and mode == 'revprop' and 1 or 0
+       return name.startswith('hg-') and mode == 'revprop' and 2 or 0

[Jun Omae]

Reconsidering, I think non-default renderer should be preferred with same quality.

trac/versioncontrol/web_ui/browser.py

@@ -770 +770 @@
             quality = renderer.match_property(name, mode)
             if quality > 0:
                 candidates.append((quality, renderer))
-        candidates.sort(reverse=True)
+        def keyfunc(candidate):
+            quality, renderer = candidate
+            # Prefer non-default renderer if the renderers have same quality
+            return quality, \
+                   0 if isinstance(renderer, DefaultPropertyRenderer) else 1, \
+                   renderer.__class__.__name__
+        candidates.sort(reverse=True, key=keyfunc)
         for (quality, renderer) in candidates:
             try:
                 rendered = renderer.render_property(name, mode, context, props)

[Jun Omae]

Fixed in [17620].