Repo: handle worktrees better

This makes Repo("foo") work when foo/.git is a file of the form created
by "git worktree add", i.e. it's a text file that says:

gitdir: /home/me/project/.git/worktrees/bar

and where /home/me/project/.git/ is the nominal gitdir, but
/home/me/project/.git/worktrees/bar has this worktree's HEAD etc and a
"gitdir" file that contains the path of foo/.git .

Signed-off-by: Peter Jones <[email protected]>

Author: vathpela

AUTHORS

@@ -18,5 +18,6 @@ Contributors are:
 -Bernard `Guyzmo` Pratz <[email protected]>
 -Timothy B. Hartman <tbhartman _at_ gmail.com>
 -Konstantin Popov <konstantin.popov.89 _at_ yandex.ru>
+-Peter Jones <pjones _at_ redhat.com>
 
 Portions derived from other open source works and are clearly marked.

git/repo/base.py

@@ -32,7 +32,7 @@
 from git.util import Actor, finalize_process, decygpath, hex_to_bin
 import os.path as osp
 
-from .fun import rev_parse, is_git_dir, find_submodule_git_dir, touch
+from .fun import rev_parse, is_git_dir, find_submodule_git_dir, touch, find_worktree_git_dir
 import gc
 import gitdb
 
@@ -138,10 +138,15 @@ def __init__(self, path=None, odbt=DefaultDBType, search_parent_directories=Fals
                 self._working_tree_dir = os.getenv('GIT_WORK_TREE', os.path.dirname(self.git_dir))
                 break
 
-            sm_gitpath = find_submodule_git_dir(osp.join(curpath, '.git'))
+            dotgit = osp.join(curpath, '.git')
+            sm_gitpath = find_submodule_git_dir(dotgit)
             if sm_gitpath is not None:
                 self.git_dir = osp.normpath(sm_gitpath)
-            sm_gitpath = find_submodule_git_dir(osp.join(curpath, '.git'))
+
+            sm_gitpath = find_submodule_git_dir(dotgit)
+            if sm_gitpath is None:
+                sm_gitpath = find_worktree_git_dir(dotgit)
+
             if sm_gitpath is not None:
                 self.git_dir = _expand_path(sm_gitpath)
                 self._working_tree_dir = curpath

git/repo/fun.py

@@ -1,5 +1,6 @@
 """Package with general repository related functions"""
 import os
+import stat
 from string import digits
 
 from git.compat import xrange
@@ -17,7 +18,7 @@
 
 
 __all__ = ('rev_parse', 'is_git_dir', 'touch', 'find_submodule_git_dir', 'name_to_object', 'short_to_long', 'deref_tag',
-           'to_commit')
+           'to_commit', 'find_worktree_git_dir')
 
 
 def touch(filename):
@@ -46,6 +47,23 @@ def is_git_dir(d):
             raise WorkTreeRepositoryUnsupported(d)
     return False
 
+def find_worktree_git_dir(dotgit):
+    """Search for a gitdir for this worktree."""
+    try:
+        statbuf = os.stat(dotgit)
+    except OSError:
+        return None
+    if not stat.S_ISREG(statbuf.st_mode):
+        return None
+
+    try:
+        lines = open(dotgit, 'r').readlines()
+        for key, value in [line.strip().split(': ') for line in lines]:
+            if key == 'gitdir':
+                return value
+    except ValueError:
+        pass
+    return None
 
 def find_submodule_git_dir(d):
     """Search for a submodule repo."""

git/test/test_repo.py

@@ -911,22 +911,21 @@ def test_is_ancestor(self):
             self.assertRaises(GitCommandError, repo.is_ancestor, i, j)
 
     @with_rw_directory
-    def test_work_tree_unsupported(self, rw_dir):
+    def test_git_work_tree_dotgit(self, rw_dir):
+        """Check that we find .git as a worktree file and find the worktree
+        based on it."""
         git = Git(rw_dir)
         if git.version_info[:3] < (2, 5, 1):
             raise SkipTest("worktree feature unsupported")
 
         rw_master = self.rorepo.clone(join_path_native(rw_dir, 'master_repo'))
-        rw_master.git.checkout('HEAD~10')
+        branch = rw_master.create_head('aaaaaaaa')
         worktree_path = join_path_native(rw_dir, 'worktree_repo')
         if Git.is_cygwin():
             worktree_path = cygpath(worktree_path)
-        try:
-            rw_master.git.worktree('add', worktree_path, 'master')
-        except Exception as ex:
-            raise AssertionError(ex, "It's ok if TC not running from `master`.")
-
-        self.failUnlessRaises(InvalidGitRepositoryError, Repo, worktree_path)
+        rw_master.git.worktree('add', worktree_path, branch.name)
+        repo = Repo(worktree_path)
+        self.assertIsInstance(repo, Repo)
 
     @with_rw_directory
     def test_git_work_tree_env(self, rw_dir):