Attached is a tar.gz of a repository the exposes the bug when a simple
'git diff' is run. If -U2 is added, the removals at the beginning of the
hunk are not shown, as expected. If -U4 is added, more changes are shown
at the beginning of the hunk, which happen to be separated by 3 lines of
context from the part that is unexpectedly visible with -U3.
-- Hannes