TypeError: unsupported operand type(s) for +: 'NoneType' and 'NoneType'

[martin]

How to Reproduce

While doing a GET operation on /changeset/9d7dc734e5f06d9adf5ff97153401863ac7705de, Trac issued an internal error.

We only have updated the submodule reference. No other changes.

Request parameters:

{'new': u'9d7dc734e5f06d9adf5ff97153401863ac7705de'}

User agent: Mozilla/5.0 (X11; OpenBSD amd64; rv:33.0) Gecko/20100101 Firefox/33.0

System Information

Trac	1.0.9
Babel	0.9.6
Docutils	0.8.1
Genshi	0.6 (with speedups)
GIT	1.7.10.4
Pygments	1.5
pysqlite	2.6.0
Python	2.7.3 (default, Jan 2 2013, 13:56:14) [GCC 4.7.2]
pytz	2012c
setuptools	0.6
SQLite	3.7.13
jQuery	1.7.2
jQuery UI	1.8.21
jQuery Timepicker	1.0.1

Enabled Plugins

TracPaste

0.2.3

Python Traceback

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/trac/web/main.py", line 554, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/local/lib/python2.7/dist-packages/trac/web/main.py", line 247, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/local/lib/python2.7/dist-packages/trac/versioncontrol/web_ui/changeset.py", line 353, in process_request
    self._render_html(req, repos, chgset, restricted, xhr, data)
  File "/usr/local/lib/python2.7/dist-packages/trac/versioncontrol/web_ui/changeset.py", line 588, in _render_html
    diff_bytes += _estimate_changes(old_node, new_node)
  File "/usr/local/lib/python2.7/dist-packages/trac/versioncontrol/web_ui/changeset.py", line 538, in _estimate_changes
    return old_size + new_size
TypeError: unsupported operand type(s) for +: 'NoneType' and 'NoneType'

[Jun Omae]

A duplicate of #10732 and #10162.