Re: Fetch/push lets a malicious server steal the targets of "have" lines

Matt McCutchen [off-list ref] writes:

Then the server generates a commit X3 that lists Y2 as a parent, even
though it doesn't have Y2, and advances 'x' to X3.  The victim fetches
'x':

           victim                  server

             Y1---Y2----                      (Y2)
            /           \                         \ 
    ---O---O---X1---X2---X3   ---O---O---X1---X2---X3

Then the server rolls back 'x' to X2:

           victim                  server

             Y1---Y2----
            /           \
    ---O---O---X1---X2---X3   ---O---O---X1---X2

Ah, I see.  My immediate reaction is that you can do worse things in
the reverse direction compared to this, but your scenario does sound
bad already.