git: key off `git` in .hg/requires rather than separate file

Differential Revision: https://phab.mercurial-scm.org/D8265

hgext/git/__init__.py

@@ -1,266 +1,275
 """grant Mercurial the ability to operate on Git repositories. (EXPERIMENTAL)
 
 This is currently super experimental. It probably will consume your
 firstborn a la Rumpelstiltskin, etc.
 """
 
 from __future__ import absolute_import
 
 import os
 
 from mercurial.i18n import _
 
 from mercurial import (
     commands,
     error,
     extensions,
     localrepo,
     pycompat,
     store,
     util,
 )
 
 from . import (
     dirstate,
     gitlog,
     gitutil,
     index,
 )
 
 # TODO: extract an interface for this in core
 class gitstore(object):  # store.basicstore):
     def __init__(self, path, vfstype):
         self.vfs = vfstype(path)
         self.path = self.vfs.base
         self.createmode = store._calcmode(self.vfs)
         # above lines should go away in favor of:
         # super(gitstore, self).__init__(path, vfstype)
 
         self.git = gitutil.get_pygit2().Repository(
             os.path.normpath(os.path.join(path, b'..', b'.git'))
         )
         self._progress_factory = lambda *args, **kwargs: None
 
     @util.propertycache
     def _db(self):
         # We lazy-create the database because we want to thread a
         # progress callback down to the indexing process if it's
         # required, and we don't have a ui handle in makestore().
         return index.get_index(self.git, self._progress_factory)
 
     def join(self, f):
         """Fake store.join method for git repositories.
 
         For the most part, store.join is used for @storecache
         decorators to invalidate caches when various files
         change. We'll map the ones we care about, and ignore the rest.
         """
         if f in (b'00changelog.i', b'00manifest.i'):
             # This is close enough: in order for the changelog cache
             # to be invalidated, HEAD will have to change.
             return os.path.join(self.path, b'HEAD')
         elif f == b'lock':
             # TODO: we probably want to map this to a git lock, I
             # suspect index.lock. We should figure out what the
             # most-alike file is in git-land. For now we're risking
             # bad concurrency errors if another git client is used.
             return os.path.join(self.path, b'hgit-bogus-lock')
         elif f in (b'obsstore', b'phaseroots', b'narrowspec', b'bookmarks'):
             return os.path.join(self.path, b'..', b'.hg', f)
         raise NotImplementedError(b'Need to pick file for %s.' % f)
 
     def changelog(self, trypending):
         # TODO we don't have a plan for trypending in hg's git support yet
         return gitlog.changelog(self.git, self._db)
 
     def manifestlog(self, repo, storenarrowmatch):
         # TODO handle storenarrowmatch and figure out if we need the repo arg
         return gitlog.manifestlog(self.git, self._db)
 
     def invalidatecaches(self):
         pass
 
     def write(self, tr=None):
         # normally this handles things like fncache writes, which we don't have
         pass
 
 
 def _makestore(orig, requirements, storebasepath, vfstype):
+    if b'git' in requirements:
+        if not os.path.exists(os.path.join(storebasepath, b'..', b'.git')):
+            raise error.Abort(
+                _(
+                    b'repository specified git format in '
+                    b'.hg/requires but has no .git directory'
+                )
+            )
     # Check for presence of pygit2 only here. The assumption is that we'll
     # run this code iff we'll later need pygit2.
     if gitutil.get_pygit2() is None:
         raise error.Abort(
             _(
                 b'the git extension requires the Python '
                 b'pygit2 library to be installed'
             )
         )
 
-    if os.path.exists(
-        os.path.join(storebasepath, b'this-is-git')
-    ) and os.path.exists(os.path.join(storebasepath, b'..', b'.git')):
         return gitstore(storebasepath, vfstype)
     return orig(requirements, storebasepath, vfstype)
 
 
 class gitfilestorage(object):
     def file(self, path):
         if path[0:1] == b'/':
             path = path[1:]
         return gitlog.filelog(self.store.git, self.store._db, path)
 
 
 def _makefilestorage(orig, requirements, features, **kwargs):
     store = kwargs['store']
     if isinstance(store, gitstore):
         return gitfilestorage
     return orig(requirements, features, **kwargs)
 
 
 def _setupdothg(ui, path):
     dothg = os.path.join(path, b'.hg')
     if os.path.exists(dothg):
         ui.warn(_(b'git repo already initialized for hg\n'))
     else:
         os.mkdir(os.path.join(path, b'.hg'))
         # TODO is it ok to extend .git/info/exclude like this?
         with open(
             os.path.join(path, b'.git', b'info', b'exclude'), 'ab'
         ) as exclude:
             exclude.write(b'\n.hg\n')
-    with open(os.path.join(dothg, b'this-is-git'), 'wb') as f:
-        pass
-    with open(os.path.join(dothg, b'requirements'), 'wb') as f:
+    with open(os.path.join(dothg, b'requires'), 'wb') as f:
         f.write(b'git\n')
 
 
 _BMS_PREFIX = 'refs/heads/'
 
 
 class gitbmstore(object):
     def __init__(self, gitrepo):
         self.gitrepo = gitrepo
 
     def __contains__(self, name):
         return (
             _BMS_PREFIX + pycompat.fsdecode(name)
         ) in self.gitrepo.references
 
     def __iter__(self):
         for r in self.gitrepo.listall_references():
             if r.startswith(_BMS_PREFIX):
                 yield pycompat.fsencode(r[len(_BMS_PREFIX) :])
 
     def __getitem__(self, k):
         return (
             self.gitrepo.references[_BMS_PREFIX + pycompat.fsdecode(k)]
             .peel()
             .id.raw
         )
 
     def get(self, k, default=None):
         try:
             if k in self:
                 return self[k]
             return default
         except gitutil.get_pygit2().InvalidSpecError:
             return default
 
     @property
     def active(self):
         h = self.gitrepo.references['HEAD']
         if not isinstance(h.target, str) or not h.target.startswith(
             _BMS_PREFIX
         ):
             return None
         return pycompat.fsencode(h.target[len(_BMS_PREFIX) :])
 
     @active.setter
     def active(self, mark):
         raise NotImplementedError
 
     def names(self, node):
         r = []
         for ref in self.gitrepo.listall_references():
             if not ref.startswith(_BMS_PREFIX):
                 continue
             if self.gitrepo.references[ref].peel().id.raw != node:
                 continue
             r.append(pycompat.fsencode(ref[len(_BMS_PREFIX) :]))
         return r
 
     # Cleanup opportunity: this is *identical* to core's bookmarks store.
     def expandname(self, bname):
         if bname == b'.':
             if self.active:
                 return self.active
             raise error.RepoLookupError(_(b"no active bookmark"))
         return bname
 
     def applychanges(self, repo, tr, changes):
         """Apply a list of changes to bookmarks
         """
         # TODO: this should respect transactions, but that's going to
         # require enlarging the gitbmstore to know how to do in-memory
         # temporary writes and read those back prior to transaction
         # finalization.
         for name, node in changes:
             if node is None:
                 self.gitrepo.references.delete(
                     _BMS_PREFIX + pycompat.fsdecode(name)
                 )
             else:
                 self.gitrepo.references.create(
                     _BMS_PREFIX + pycompat.fsdecode(name),
                     gitutil.togitnode(node),
                     force=True,
                 )
 
 
 def init(orig, ui, dest=b'.', **opts):
     if opts.get('git', False):
         path = os.path.abspath(dest)
         # TODO: walk up looking for the git repo
         _setupdothg(ui, path)
         return 0
     return orig(ui, dest=dest, **opts)
 
 
 def reposetup(ui, repo):
     if isinstance(repo.store, gitstore):
         orig = repo.__class__
         repo.store._progress_factory = repo.ui.makeprogress
 
         class gitlocalrepo(orig):
             def _makedirstate(self):
                 # TODO narrow support here
                 return dirstate.gitdirstate(
                     self.ui, self.vfs.base, self.store.git
                 )
 
             def commit(self, *args, **kwargs):
                 ret = orig.commit(self, *args, **kwargs)
                 tid = self.store.git[gitutil.togitnode(ret)].tree.id
                 # DANGER! This will flush any writes staged to the
                 # index in Git, but we're sidestepping the index in a
                 # way that confuses git when we commit. Alas.
                 self.store.git.index.read_tree(tid)
                 self.store.git.index.write()
                 return ret
 
             @property
             def _bookmarks(self):
                 return gitbmstore(self.store.git)
 
         repo.__class__ = gitlocalrepo
     return repo
 
 
+def _featuresetup(ui, supported):
+    # don't die on seeing a repo with the git requirement
+    supported |= {b'git'}
+
+
 def extsetup(ui):
     extensions.wrapfunction(localrepo, b'makestore', _makestore)
     extensions.wrapfunction(localrepo, b'makefilestorage', _makefilestorage)
     # Inject --git flag for `hg init`
     entry = extensions.wrapcommand(commands.table, b'init', init)
     entry[1].extend(
         [(b'', b'git', None, b'setup up a git repository instead of hg')]
     )
+    localrepo.featuresetupfuncs.add(_featuresetup)

tests/test-git-interop.t

@@ -1,230 +1,250
 #require pygit2
 
 Setup:
-  > GIT_AUTHOR_NAME='test'; export GIT_AUTHOR_NAME
+  $ GIT_AUTHOR_NAME='test'; export GIT_AUTHOR_NAME
   > GIT_AUTHOR_EMAIL='[e-mail]'; export GIT_AUTHOR_EMAIL
   > GIT_AUTHOR_DATE="2007-01-01 00:00:00 +0000"; export GIT_AUTHOR_DATE
   > GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; export GIT_COMMITTER_NAME
   > GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"; export GIT_COMMITTER_EMAIL
   > GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"; export GIT_COMMITTER_DATE
-
   > count=10
   > gitcommit() {
   >    GIT_AUTHOR_DATE="2007-01-01 00:00:$count +0000";
   >    GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"
   >    git commit "$@" >/dev/null 2>/dev/null || echo "git commit error"
   >    count=`expr $count + 1`
   >  }
 
-  > echo "[extensions]" >> $HGRCPATH
+
+Test auto-loading extension works:
+  $ mkdir nogit
+  $ cd nogit
+  $ mkdir .hg
+  $ echo git >> .hg/requires
+  $ hg status
+  abort: repository specified git format in .hg/requires but has no .git directory
+  [255]
+  $ git init
+  Initialized empty Git repository in $TESTTMP/nogit/.git/
+This status invocation shows some hg gunk because we didn't use
+`hg init --git`, which fixes up .git/info/exclude for us.
+  $ hg status
+  ? .hg/cache/git-commits.sqlite
+  ? .hg/cache/git-commits.sqlite-shm
+  ? .hg/cache/git-commits.sqlite-wal
+  ? .hg/requires
+  $ cd ..
+
+Now globally enable extension for the rest of the test:
+  $ echo "[extensions]" >> $HGRCPATH
   > echo "git=" >> $HGRCPATH
 
 Make a new repo with git:
   $ mkdir foo
   $ cd foo
   $ git init
   Initialized empty Git repository in $TESTTMP/foo/.git/
 Ignore the .hg directory within git:
   $ echo .hg >> .git/info/exclude
   $ echo alpha > alpha
   $ git add alpha
   $ gitcommit -am 'Add alpha'
   $ echo beta > beta
   $ git add beta
   $ gitcommit -am 'Add beta'
   $ echo gamma > gamma
   $ git status
   On branch master
   Untracked files:
     (use "git add <file>..." to include in what will be committed)
   	gamma
   
   nothing added to commit but untracked files present (use "git add" to track)
 
 Without creating the .hg, hg status fails:
   $ hg status
   abort: no repository found in '$TESTTMP/foo' (.hg not found)!
   [255]
 But if you run hg init --git, it works:
   $ hg init --git
   $ hg id --traceback
   3d9be8deba43 tip master
   $ hg status
   ? gamma
 Log works too:
   $ hg log
   changeset:   1:3d9be8deba43
   bookmark:    master
   tag:         tip
   user:        test <[e-mail]>
   date:        Mon Jan 01 00:00:11 2007 +0000
   summary:     Add beta
   
   changeset:   0:c5864c9d16fb
   user:        test <[e-mail]>
   date:        Mon Jan 01 00:00:10 2007 +0000
   summary:     Add alpha
   
 
 
 and bookmarks:
   $ hg bookmarks
    * master                    1:3d9be8deba43
 
 diff even works transparently in both systems:
   $ echo blah >> alpha
   $ git diff
   diff --git a/alpha b/alpha
   index 4a58007..faed1b7 100644
   --- a/alpha
   +++ b/alpha
   @@ -1* +1,2 @@ (glob)
    alpha
   +blah
   $ hg diff --git
   diff --git a/alpha b/alpha
   --- a/alpha
   +++ b/alpha
   @@ -1,1 +1,2 @@
    alpha
   +blah
 
 Remove a file, it shows as such:
   $ rm alpha
   $ hg status
   ! alpha
   ? gamma
 
 Revert works:
   $ hg revert alpha --traceback
   $ hg status
   ? gamma
   $ git status
   On branch master
   Untracked files:
     (use "git add <file>..." to include in what will be committed)
   	gamma
   
   nothing added to commit but untracked files present (use "git add" to track)
 
 Add shows sanely in both:
   $ hg add gamma
   $ hg status
   A gamma
   $ hg files
   alpha
   beta
   gamma
   $ git ls-files
   alpha
   beta
   gamma
   $ git status
   On branch master
   Changes to be committed:
     (use "git restore --staged <file>..." to unstage)
   	new file:   gamma
   
 
 forget does what it should as well:
   $ hg forget gamma
   $ hg status
   ? gamma
   $ git status
   On branch master
   Untracked files:
     (use "git add <file>..." to include in what will be committed)
   	gamma
   
   nothing added to commit but untracked files present (use "git add" to track)
 
 clean up untracked file
   $ rm gamma
 
 hg log FILE
 
   $ echo a >> alpha
   $ hg ci -m 'more alpha' --traceback --date '1583522787 18000'
   $ echo b >> beta
   $ hg ci -m 'more beta'
   $ echo a >> alpha
   $ hg ci -m 'even more alpha'
   $ hg log -G alpha
   @  changeset:   4:6626247b7dc8
   :  bookmark:    master
   :  tag:         tip
   :  user:        test <test>
   :  date:        Thu Jan 01 00:00:00 1970 +0000
   :  summary:     even more alpha
   :
   o  changeset:   2:a1983dd7fb19
   :  user:        test <test>
   :  date:        Fri Mar 06 14:26:27 2020 -0500
   :  summary:     more alpha
   :
   o  changeset:   0:c5864c9d16fb
      user:        test <[e-mail]>
      date:        Mon Jan 01 00:00:10 2007 +0000
      summary:     Add alpha
   
   $ hg log -G beta
   o  changeset:   3:d8ee22687733
   :  user:        test <test>
   :  date:        Thu Jan 01 00:00:00 1970 +0000
   :  summary:     more beta
   :
   o  changeset:   1:3d9be8deba43
   |  user:        test <[e-mail]>
   ~  date:        Mon Jan 01 00:00:11 2007 +0000
      summary:     Add beta
   
 
 hg annotate
 
   $ hg annotate alpha
   0: alpha
   2: a
   4: a
   $ hg annotate beta
   1: beta
   3: b
 
 
 Files in subdirectories. TODO: case-folding support, make this `A`
 instead of `a`.
 
   $ mkdir a
   $ echo "This is file mu." > a/mu
   $ hg ci -A -m 'Introduce file a/mu'
   adding a/mu
 
 Both hg and git agree a/mu is part of the repo
 
   $ git ls-files
   a/mu
   alpha
   beta
   $ hg files
   a/mu
   alpha
   beta
 
 hg and git status both clean
 
   $ git status
   On branch master
   nothing to commit, working tree clean
   $ hg status
 
 
 node|shortest works correctly
   $ hg log -T '{node}\n' | sort
   3d9be8deba43482be2c81a4cb4be1f10d85fa8bc
   6626247b7dc8f231b183b8a4761c89139baca2ad
   a1983dd7fb19cbd83ad5a1c2fc8bf3d775dea12f
   ae1ab744f95bfd5b07cf573baef98a778058537b
   c5864c9d16fb3431fe2c175ff84dc6accdbb2c18
   d8ee22687733a1991813560b15128cd9734f4b48
   $ hg log -r ae1ab744f95bfd5b07cf573baef98a778058537b --template "{shortest(node,1)}\n"
   ae