tests/test-issue672.t

dirstate: prevent useless util.fspath() invocation for '.'

at first of dirstate.walk() on case insensitive filesystem,
normalization of '.' causes util.fspath() invocation, but '.' is not
cached in it.

this invocation is not only useless, but also harmful: initial "hg
tag" causes creation of ".hgtags" file after dirstate.walk(), and
looking up ".hgtags" in cache will fail, because directory contents of
root is already cached at util.fspath() invocation for '.'.

http://mercurial.selenic.com/bts/issue672

# 0-2-4
#  \ \ \
#   1-3-5
#
# rename in #1, content change in #4.

  $ hg init

  $ touch 1
  $ touch 2
  $ hg commit -Am init  # 0
  adding 1
  adding 2

  $ hg rename 1 1a
  $ hg commit -m rename # 1

  $ hg co -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo unrelated >> 2
  $ hg ci -m unrelated1 # 2
  created new head

  $ hg merge --debug 1
    searching for copies back to rev 1
    unmatched files in other:
     1a
    all copies found (* = to merge, ! = divergent):
     1a -> 1 
    checking for directory renames
  resolving manifests
   overwrite None partial False
   ancestor 81f4b099af3d local c64f439569a9+ remote c12dcd37c90a
   1: other deleted -> r
   1a: remote created -> g
  updating: 1 1/2 files (50.00%)
  removing 1
  updating: 1a 2/2 files (100.00%)
  getting 1a
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg ci -m merge1 # 3

  $ hg co -C 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo hello >> 1
  $ hg ci -m unrelated2 # 4
  created new head

  $ hg co -C 3
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg merge -y --debug 4
    searching for copies back to rev 1
    unmatched files in local:
     1a
    all copies found (* = to merge, ! = divergent):
     1a -> 1 *
    checking for directory renames
  resolving manifests
   overwrite None partial False
   ancestor c64f439569a9 local e327dca35ac8+ remote 746e9549ea96
   1a: local copied/moved to 1 -> m
  preserving 1a for resolve of 1a
  updating: 1a 1/1 files (100.00%)
  picked tool 'internal:merge' for 1a (binary False symlink False)
  merging 1a and 1 to 1a
  my 1a@e327dca35ac8+ other 1@746e9549ea96 ancestor 1@81f4b099af3d
   premerge successful
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg co -C 4
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg merge -y --debug 3
    searching for copies back to rev 1
    unmatched files in other:
     1a
    all copies found (* = to merge, ! = divergent):
     1a -> 1 *
    checking for directory renames
  resolving manifests
   overwrite None partial False
   ancestor c64f439569a9 local 746e9549ea96+ remote e327dca35ac8
   1: remote moved to 1a -> m
  preserving 1 for resolve of 1a
  removing 1
  updating: 1 1/1 files (100.00%)
  picked tool 'internal:merge' for 1a (binary False symlink False)
  merging 1 and 1a to 1a
  my 1a@746e9549ea96+ other 1a@e327dca35ac8 ancestor 1@81f4b099af3d
   premerge successful
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)