The "/vdiff" page:

Show the difference between two check-ins identified by the from= and to= query parameters.

Query parameters:

from=TAG

Left side of the comparison

to=TAG

Right side of the comparison

branch=TAG

Show all changes on a particular branch

diff=INTEGER

0: none, 1: unified, 2: side-by-side

glob=STRING

only diff files matching this glob

dc=N

show N lines of context around each diff

w=BOOLEAN

ignore whitespace when computing diffs

nohdr

omit the description at the top of the page

nc

omit branch coloration from the header graph

inv

"Invert". Exchange the roles of from= and to=

Show all differences between two check-ins.