lfs: autoload the extension when cloning from repo with lfs enabled
This is based on a patch by Gregory Szorc. I made small adjustments to
clean up the messaging when the server has the extension enabled, but the
client has it disabled (to prevent autoloading). Additionally, I added
a second server capability to distinguish between the server having the
extension enabled, and the server having LFS commits. This helps prevent
unnecessary requirement propagation- the client shouldn't add a requirement
that the server doesn't have, just because the server had the extension
loaded. The TODO I had about advertising a capability when the server can
natively serve up blobs isn't relevant anymore (we've had 2 releases that
support this), so I dropped it.
Currently, we lazily add the "lfs" requirement to a repo when we first
encounter LFS data. Due to a pretxnchangegroup hook that looks for LFS
data, this can happen at the end of clone.
Now that we have more control over how repositories are created, we can
do better.
This commit adds a repo creation option to add the "lfs" requirement.
hg.clone() sets this creation option if the remote peer is advertising
lfs usage (as opposed to just support needed to push).
So, what this change effectively does is have cloned repos
automatically inherit the "lfs" requirement.
Differential Revision: https://phab.mercurial-scm.org/D5130
#require symlink
Create extension that can disable symlink support:
$ cat > nolink.py <<EOF
> from mercurial import extensions, util
> def setflags(orig, f, l, x):
> pass
> def checklink(orig, path):
> return False
> def extsetup(ui):
> extensions.wrapfunction(util, 'setflags', setflags)
> extensions.wrapfunction(util, 'checklink', checklink)
> EOF
$ hg init unix-repo
$ cd unix-repo
$ echo foo > a
$ ln -s a b
$ hg ci -Am0
adding a
adding b
$ cd ..
Simulate a checkout shared on NFS/Samba:
$ hg clone -q unix-repo shared
$ cd shared
$ rm b
$ echo foo > b
$ hg --config extensions.n=$TESTTMP/nolink.py status --debug
ignoring suspect symlink placeholder "b"
Make a clone using placeholders:
$ hg --config extensions.n=$TESTTMP/nolink.py clone . ../win-repo
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ../win-repo
$ cat b
a (no-eol)
$ hg --config extensions.n=$TESTTMP/nolink.py st --debug
Empty placeholder:
$ rm b
$ touch b
$ hg --config extensions.n=$TESTTMP/nolink.py st --debug
ignoring suspect symlink placeholder "b"
Write binary data to the placeholder:
>>> open('b', 'w').write('this is a binary\0') and None
$ hg --config extensions.n=$TESTTMP/nolink.py st --debug
ignoring suspect symlink placeholder "b"
Write a long string to the placeholder:
>>> open('b', 'w').write('this' * 1000) and None
$ hg --config extensions.n=$TESTTMP/nolink.py st --debug
ignoring suspect symlink placeholder "b"
Commit shouldn't succeed:
$ hg --config extensions.n=$TESTTMP/nolink.py ci -m1
nothing changed
[1]
Write a valid string to the placeholder:
>>> open('b', 'w').write('this') and None
$ hg --config extensions.n=$TESTTMP/nolink.py st --debug
M b
$ hg --config extensions.n=$TESTTMP/nolink.py ci -m1
$ hg manifest tip --verbose
644 a
644 @ b
$ cd ..