D7106: fuzz: restrict dirs fuzzer to only 40k of input

[durin42 (Augie Fackler)]

durin42 added a comment.


  The concern is basically that the fuzzer will figure out something dumb, like `'a/' * 40000 + 'b'` which consumes around a gig of memory. I don't think this is a serious OOM vector, since any such manifest would also be inordinately large?
  
  Maybe I'm being an optimist.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7106/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7106

To: durin42, #hg-reviewers
Cc: indygreg, mercurial-devel