tests/test-casecollision.t

filelog: don't crash on invalid copy metadata (issue5748)

"copy" and "copyrev" are both supposed to appear next to each other.
However, a user report demonstrated a crash that indicates that
something in the wild is producing "copy" without "copyrev"
(probably `hg convert`).

While we should definitely fix the source of the bad metadata,
the bad code causing the crash is already in the wild and who knows
how many repositories are impacted. So let's be more defensive
when accessing the file revision metadata.

#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 ..