bundle: move file chunk generation to it's own function
Moves the file chunk generation part of bundle creation to it's own function.
This allows extensions to customize the filelog part of bundle generation.
$ hg init outer
$ cd outer
$ echo '[paths]' >> .hg/hgrc
$ echo 'default = http://example.net/' >> .hg/hgrc
hg debugsub with no remapping
$ echo 'sub = libfoo' > .hgsub
$ hg add .hgsub
$ hg debugsub
path sub
source libfoo
revision
hg debugsub with remapping
$ echo '[subpaths]' >> .hg/hgrc
$ printf 'http://example.net/lib(.*) = C:\\libs\\\\1-lib\\\n' >> .hg/hgrc # no-check-code
$ hg debugsub
path sub
source C:\libs\foo-lib\
revision
test cumulative remapping, the $HGRCPATH file is loaded first
$ echo '[subpaths]' >> $HGRCPATH
$ echo 'libfoo = libbar' >> $HGRCPATH
$ hg debugsub
path sub
source C:\libs\bar-lib\
revision
test absolute source path -- testing with a URL is important since
standard os.path.join wont treat that as an absolute path
$ echo 'abs = http://example.net/abs' > .hgsub
$ hg debugsub
path abs
source http://example.net/abs
revision
$ echo 'abs = /abs' > .hgsub
$ hg debugsub
path abs
source /abs
revision
test bad subpaths pattern
$ cat > .hg/hgrc <<EOF
> [subpaths]
> .* = \1
> EOF
$ hg debugsub
abort: bad subrepository pattern in $TESTTMP/outer/.hg/hgrc:2: invalid group reference (glob)
[255]
$ cd ..