setdiscovery: return anyincoming=False when remote's only head is nullid This fixes (issue2907) a crash when using 'hg incoming --bundle' with an empty remote repo and a non-empty local repo. This also fixes an unreported bug that 'hg summary --remote' erroneously reports incoming changes when the remote repo is empty and the local is not. Also, add a test to make sure issue2907 stays fixed

  $ hg init
  $ echo a > a
  $ hg ci -Am t
  adding a

  $ hg mv a b
  $ hg ci -Am t1
  $ hg debugrename b
  b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3

  $ hg mv b a
  $ hg ci -Am t2
  $ hg debugrename a
  a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980

  $ hg debugrename --rev 1 b
  b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3