Diff URLs in Bamboo have an illegal parameter that causes an exception in viewVC. Removing the bad parameter causes ViewVC to work as expected.

viewVC URL format docs:
http://viewvc.tigris.org/source/browse/*checkout*/viewvc/trunk/docs/url-reference.html?rev=1509#diff-view

Example of bad diff URL from Bamboo:
http://opensecondlife.org/svn/index.cgi/libsl/trunk/libsecondlife-cs/LLObject.cs?content-type=text/vnd.viewcvs-markup&root=&rev=947&r=947&r1=946&r2=947

An Exception Has Occurred

An illegal parameter name ("r") was passed.

HTTP Response Status

400 Bad Request

Python Traceback

Traceback (most recent call last):
File "/usr/local/viewvc-1.0.3/lib/viewvc.py", line 3629, in main
request.run_viewvc()
File "/usr/local/viewvc-1.0.3/lib/viewvc.py", line 161, in run_viewvc
_validate_param(name, values[0])
File "/usr/local/viewvc-1.0.3/lib/viewvc.py", line 598, in _validate_param
'400 Bad Request')
ViewVCException: 400 Bad Request: An illegal parameter name ("r") was passed.