tests/test-casecollision.t

manifest: document return type of readfast()

I keep having to ponder out what readfast() means, and it always
surprises me. Document the return type in the docstring so that future
readers won't have to puzzle this out again.

#require no-icasefs

test file addition with colliding case

  $ hg init repo1
  $ cd repo1
  $ echo a > a
  $ echo A > A
  $ hg add a
  $ hg st
  A a
  ? A
  $ hg add --config ui.portablefilenames=abort A
  abort: possible case-folding collision for A
  [255]
  $ hg st
  A a
  ? A
  $ hg add A
  warning: possible case-folding collision for A
  $ hg st
  A A
  A a
  $ hg forget A
  $ hg st
  A a
  ? A
  $ hg add --config ui.portablefilenames=no A
  $ hg st
  A A
  A a
  $ mkdir b
  $ touch b/c b/D
  $ hg add b
  adding b/D
  adding b/c
  $ touch b/d b/C
  $ hg add b/C
  warning: possible case-folding collision for b/C
  $ hg add b/d
  warning: possible case-folding collision for b/d
  $ touch b/a1 b/a2
  $ hg add b
  adding b/a1
  adding b/a2
  $ touch b/A2 b/a1.1
  $ hg add b/a1.1 b/A2
  warning: possible case-folding collision for b/A2
  $ touch b/f b/F
  $ hg add b/f b/F
  warning: possible case-folding collision for b/f
  $ touch g G
  $ hg add g G
  warning: possible case-folding collision for g
  $ mkdir h H
  $ touch h/x H/x
  $ hg add h/x H/x
  warning: possible case-folding collision for h/x
  $ touch h/s H/s
  $ hg add h/s
  $ hg add H/s
  warning: possible case-folding collision for H/s

case changing rename must not warn or abort

  $ echo c > c
  $ hg ci -qAmx
  $ hg mv c C
  $ cd ..