vfs: extract 'vfs' class and related code to a new 'vfs' module (API)
The 'scmutil' is growing large (1500+ lines) and 2/5 of it is related to vfs.
We extract the 'vfs' related code in its own module get both module back to a
better scale and clearer contents.
We keep all the references available in 'scmutil' for now as many reference
needs to be updated.
#require symlink
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ hg qinit
$ hg qnew base.patch
$ echo aaa > a
$ echo bbb > b
$ echo ccc > c
$ hg add a b c
$ hg qrefresh
$ readlink.py a
a -> a not a symlink
test replacing a file with a symlink
$ hg qnew symlink.patch
$ rm a
$ ln -s b a
$ hg qrefresh --git
$ readlink.py a
a -> b
$ hg qpop
popping symlink.patch
now at: base.patch
$ hg qpush
applying symlink.patch
now at: symlink.patch
$ readlink.py a
a -> b
test updating a symlink
$ rm a
$ ln -s c a
$ hg qnew --git -f updatelink
$ readlink.py a
a -> c
$ hg qpop
popping updatelink
now at: symlink.patch
$ hg qpush --debug
applying updatelink
patching file a
committing files:
a
committing manifest
committing changelog
now at: updatelink
$ readlink.py a
a -> c
$ hg st
test replacing a symlink with a file
$ ln -s c s
$ hg add s
$ hg qnew --git -f addlink
$ rm s
$ echo sss > s
$ hg qnew --git -f replacelinkwithfile
$ hg qpop
popping replacelinkwithfile
now at: addlink
$ hg qpush
applying replacelinkwithfile
now at: replacelinkwithfile
$ cat s
sss
$ hg st
test symlink removal
$ hg qnew removesl.patch
$ hg rm a
$ hg qrefresh --git
$ hg qpop
popping removesl.patch
now at: replacelinkwithfile
$ hg qpush
applying removesl.patch
now at: removesl.patch
$ hg st -c
C b
C c
C s
replace broken symlink with another broken symlink
$ ln -s linka linka
$ hg add linka
$ hg qnew link
$ hg mv linka linkb
$ rm linkb
$ ln -s linkb linkb
$ hg qnew movelink
$ hg qpop
popping movelink
now at: link
$ hg qpush
applying movelink
now at: movelink
$ readlink.py linkb
linkb -> linkb