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 dir
$ cd dir
$ echo bleh > bar
$ hg add bar
$ hg ci -m 'add bar'
$ hg cp bar foo
$ echo >> bar
$ hg ci -m 'cp bar foo; change bar'
$ hg debugrename foo
foo renamed from bar:26d3ca0dfd18e44d796b564e38dd173c9668d3a9
$ hg debugindex bar
rev offset length base linkrev nodeid p1 p2
0 0 6 0 0 26d3ca0dfd18 000000000000 000000000000
1 6 7 1 1 d267bddd54f7 26d3ca0dfd18 000000000000