tests/test-manifest-merging.t

dirstate: avoid normalizing letter case on icasefs for exact match (issue3340)

on icasefs, "hg qnew" fails to import changing letter case of filename
already occurred in working directory, for example:

    $ hg rename a tmp
    $ hg rename tmp A
    $ hg qnew casechange
    $ hg status
    R a
    $

"hg qnew" invokes 'dirstate.walk()' via 'localrepository.commit()'
with 'exact match' matching object having exact filenames of targets
in ones 'files()'.

current implementation of 'dirstate.walk()' always normalizes letter
case of filenames from 'match.files()' on icasefs, even though exact
matching is required.

then, files only different in letter case are treated as one file.

this patch prevents 'dirstate.walk()' from normalizing, if exact
matching is required, even on icasefs.

filenames for 'exact matching' are given not from user command line,
but from dirstate walk result, manifest of changecontext, patch files
or fixed list for specific system files (e.g.: '.hgtags').

in such case, case normalization should not be done, so this patch
works well.

  $ hg init base

  $ cd base
  $ echo 'alpha' > alpha
  $ hg ci -A -m 'add alpha'
  adding alpha
  $ cd ..

  $ hg clone base work
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd work
  $ echo 'beta' > beta
  $ hg ci -A -m 'add beta'
  adding beta
  $ cd ..

  $ cd base
  $ echo 'gamma' > gamma
  $ hg ci -A -m 'add gamma'
  adding gamma
  $ cd ..

  $ cd work
  $ hg pull -q
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Update --clean to revision 1 to simulate a failed merge:

  $ rm alpha beta gamma
  $ hg update --clean 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved