git: support simple clone

Summary: Support cloning a git repo using `git+` URLs.

Reviewed By: DurhamG

Differential Revision: D33351383

fbshipit-source-id: 684ac78111b201e44256b0dfebe2aa52d46f7693

eden/scm/edenscm/hgext/remotefilelog/__init__.py

@@ -145,6 +145,7 @@ from edenscm.mercurial import (
     error,
     exchange,
     extensions,
+    git,
     hg,
     localrepo,
     match,
@@ -290,8 +291,10 @@ def wrappackers():
         packermap["03"] = (shallowbundle.shallowcg3packer, packermap03[1])
 
 
-def cloneshallow(orig, ui, repo, *args, **opts):
-    if opts.get("shallow"):
+def cloneshallow(orig, ui, source, *args, **opts):
+    # skip for (full) git repos
+    giturl = git.maybegiturl(source)
+    if opts.get("shallow") and giturl is None:
         repos = []
 
         def pull_shallow(orig, self, *args, **kwargs):
@@ -333,7 +336,7 @@ def cloneshallow(orig, ui, repo, *args, **opts):
 
         wrapfunction(localrepo, "newreporequirements", newreporequirements)
 
-    orig(ui, repo, *args, **opts)
+    orig(ui, source, *args, **opts)
 
 
 def debugdatashallow(orig, *args, **kwds):

eden/scm/edenscm/mercurial/commands/__init__.py

@@ -1618,18 +1618,25 @@ def clone(ui, source, dest=None, **opts):
     """
     if opts.get("noupdate") and opts.get("updaterev"):
         raise error.Abort(_("cannot specify both --noupdate and --updaterev"))
-
-    r = hg.clone(
-        ui,
-        opts,
-        source,
-        dest,
-        pull=opts.get("pull"),
-        stream=opts.get("stream") or opts.get("uncompressed"),
-        rev=opts.get("rev"),
-        update=opts.get("updaterev") or not opts.get("noupdate"),
-        shallow=opts.get("shallow"),
-    )
+    giturl = git.maybegiturl(source)
+    if giturl is not None:
+        if opts.get("noupdate"):
+            update = False
+        else:
+            update = opts.get("updaterev") or True
+        r = git.clone(ui, giturl, dest, update)
+    else:
+        r = hg.clone(
+            ui,
+            opts,
+            source,
+            dest,
+            pull=opts.get("pull"),
+            stream=opts.get("stream") or opts.get("uncompressed"),
+            rev=opts.get("rev"),
+            update=opts.get("updaterev") or not opts.get("noupdate"),
+            shallow=opts.get("shallow"),
+        )
 
     return r is None
 

eden/scm/edenscm/mercurial/commands/debug.py

@@ -1557,12 +1557,7 @@ def debuginitgit(ui, destpath, **opts):
     if not os.path.exists(os.path.join(gitdir, "refs")):
         raise error.Abort(_("invalid --git-dir: %s") % gitdir)
     repo = hg.repository(ui, ui.expandpath(destpath), create=True).local()
-    with repo.lock(), repo.transaction("initgit"):
-        repo.svfs.writeutf8(git.GIT_DIR_FILE, gitdir)
-        repo.storerequirements.add(git.GIT_REQUIREMENT)
-        repo._writestorerequirements()
-        repo.invalidatechangelog()
-        visibility.add(repo, repo.changelog.dageval(lambda: heads(all())))
+    git.initgit(repo, gitdir)
 
 
 @command("debuginstall", [] + cmdutil.formatteropts, "", norepo=True)

eden/scm/edenscm/mercurial/git.py

@@ -8,6 +8,8 @@ utilities for git support
 """
 
 import hashlib
+import os
+import shutil
 import subprocess
 
 import bindings
@@ -39,11 +41,107 @@ def isgit(repo):
     return GIT_REQUIREMENT in repo.storerequirements
 
 
+def clone(ui, url, destpath=None, update=True):
+    """Clone a git repo, then create a repo at dest backed by the git repo.
+    update can be False, or True, or a node to update to.
+    - False: do not update, leave an empty working copy.
+    - True: upate to git HEAD.
+    - other: update to `other` (node, or name).
+    """
+    from . import hg
+
+    if destpath is None:
+        # use basename as fallback, but strip ".git" or "/.git".
+        basename = os.path.basename(url)
+        if basename == ".git":
+            basename = os.path.basename(os.path.dirname(url))
+        elif basename.endswith(".git"):
+            basename = basename[:-4]
+        destpath = os.path.realpath(basename)
+
+    repo = hg.repository(ui, ui.expandpath(destpath), create=True).local()
+    try:
+        ret = clonegitbare(ui, url, repo.svfs.join("git"))
+        if ret != 0:
+            raise error.Abort(_("git clone was not successful"))
+        initgit(repo, "git")
+    except Exception:
+        repo = None
+        shutil.rmtree(destpath, ignore_errors=True)
+        raise
+    if update is not False:
+        if update is True:
+            update = None
+        postpullupdate(repo, update)
+    return repo
+
+
+def initgit(repo, gitdir):
+    """Change a repo to be backed by a bare git repo in `gitdir`.
+    This should only be called for newly created repos.
+    """
+    from . import visibility
+
+    hgrc = "%include builtin:git.rc\n"
+
+    with repo.lock(), repo.transaction("initgit"):
+        repo.svfs.writeutf8(GIT_DIR_FILE, gitdir)
+        repo.storerequirements.add(GIT_REQUIREMENT)
+        repo._writestorerequirements()
+        repo.invalidatechangelog()
+        visibility.add(repo, repo.changelog.dageval(lambda: heads(all())))
+        repo.sharedvfs.writeutf8("hgrc", hgrc)
+        repo.ui.reloadconfigs(repo.root)
+
+
+def maybegiturl(url):
+    """Return normalized url if url is a git url, or None otherwise.
+
+    For now url schemes "git", "git+file", "git+ftp", "git+http", "git+https",
+    "git+ssh" are considered git urls. The "git+" part will be stripped.
+    """
+    parsed = util.url(url)
+    if parsed.scheme == "git":
+        return url
+    if parsed.scheme in {
+        "git+file",
+        "git+ftp",
+        "git+ftps",
+        "git+http",
+        "git+https",
+        "git+ssh",
+    }:
+        if url.startswith("git+"):
+            return url[4:]
+    return None
+
+
+def clonegitbare(ui, giturl, destpath):
+    """Clone a git repo into local path `dest` as a git bare repo.
+    This does not prepare working copy or `.hg`.
+    """
+    # not using 'git clone --bare' because it writes refs to refs/heads/,
+    # not in desirable refs/remotes/origin/heads/.
+    for gitdir, cmd in [
+        (None, ["init", "-q", "-b", "default", "--bare", destpath]),
+        (destpath, ["remote", "add", "origin", giturl]),
+        (destpath, ["fetch", "origin"]),
+    ]:
+        ret = rungitnorepo(ui, cmd, gitdir=gitdir)
+        if ret != 0:
+            return ret
+    return 0
+
+
 @cached
 def readgitdir(repo):
     """Return the path of the GIT_DIR, if the repo is backed by git"""
     if isgit(repo):
-        return repo.svfs.readutf8(GIT_DIR_FILE)
+        path = repo.svfs.readutf8(GIT_DIR_FILE)
+        if os.path.isabs(path):
+            return path
+        else:
+            return repo.svfs.join(path)
     else:
         return None
 

eden/scm/tests/test-git.t

@@ -176,3 +176,33 @@ Test pull:
 
 - infinitepush compatibility
   $ hg pull --config extensions.infinitepush=
+
+Test clone with flags (--noupdate, --updaterev):
+
+  $ mkdir $TESTTMP/clonetest
+  $ cd $TESTTMP/clonetest
+
+  $ hg clone -q --noupdate "git+file://$TESTTMP/gitrepo"
+  $ cd gitrepo
+  $ hg log -r . -T '{node|short}\n'
+  000000000000
+  $ cd ..
+
+  $ hg clone "git+file://$TESTTMP/gitrepo" cloned1
+  From file:/*/$TESTTMP/gitrepo (glob)
+   * [new branch]      foo        -> origin/foo
+   * [new branch]      master     -> origin/master
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg --cwd cloned1 log -r . -T '{node|short} {remotenames} {desc}\n'
+  5c9a5ee451a8 origin/foo alpha3
+  $ cd ..
+
+  $ hg clone --updaterev origin/foo "git+file://$TESTTMP/gitrepo" cloned2
+  From file:/*/$TESTTMP/gitrepo (glob)
+   * [new branch]      foo        -> origin/foo
+   * [new branch]      master     -> origin/master
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg --cwd cloned2 log -r . -T '{node|short} {remotenames} {desc}\n'
+  5c9a5ee451a8 origin/foo alpha3
+  $ cd ..
+