Implemented Submodule.rename()

A test verifies it's truly working.

Related to #238

Author: Byron

doc/source/changes.rst

@@ -6,6 +6,8 @@ Changelog
 ================
 * Added `Repo.merge_base()` implementation. See the `respective issue on github <https://github.com/gitpython-developers/GitPython/issues/169>`_
 * `[include]` sections in git configuration files are now respected
+* Added `GitConfigParser.rename_section()`
+* Added `Submodule.rename()`
 * A list of all issues can be found here: https://github.com/gitpython-developers/GitPython/issues?q=milestone%3A%22v0.3.6+-+Features%22+
 
 0.3.5 - Bugfixes

git/config.py

@@ -478,8 +478,6 @@ def _assure_writable(self, method_name):
         if self.read_only:
             raise IOError("Cannot execute non-constant method %s.%s" % (self, method_name))
 
-    @needs_values
-    @set_dirty_and_flush_changes
     def add_section(self, section):
         """Assures added options will stay in order"""
         return super(GitConfigParser, self).add_section(section)
@@ -546,3 +544,23 @@ def set_value(self, section, option, value):
         if not self.has_section(section):
             self.add_section(section)
         self.set(section, option, str(value))
+
+    def rename_section(self, section, new_name):
+        """rename the given section to new_name
+        :raise ValueError: if section doesn't exit
+        :raise ValueError: if a section with new_name does already exist
+        :return: this instance
+        """
+        if not self.has_section(section):
+            raise ValueError("Source section '%s' doesn't exist" % section)
+        if self.has_section(new_name):
+            raise ValueError("Destination section '%s' already exists" % new_name)
+
+        super(GitConfigParser, self).add_section(new_name)
+        for k, v in self.items(section):
+            self.set(new_name, k, str(v))
+        # end for each value to copy
+
+        # This call writes back the changes, which is why we don't have the respective decorator
+        self.remove_section(section)
+        return self

git/objects/submodule/base.py

@@ -109,7 +109,12 @@ def __init__(self, repo, binsha, mode=None, path=None, name=None, parent_commit=
     def _set_cache_(self, attr):
         if attr == '_parent_commit':
             # set a default value, which is the root tree of the current head
-            self._parent_commit = self.repo.commit()
+            try:
+                self._parent_commit = self.repo.commit()
+            except ValueError:
+                # This fails in an empty repository.
+                self._parent_commit = None
+            # end exception handling
         elif attr in ('path', '_url', '_branch_path'):
             reader = self.config_reader()
             # default submodule values
@@ -163,7 +168,13 @@ def _config_parser(cls, repo, parent_commit, read_only):
         :raise IOError: If the .gitmodules file cannot be found, either locally or in the repository
             at the given parent commit. Otherwise the exception would be delayed until the first
             access of the config parser"""
-        parent_matches_head = repo.head.commit == parent_commit
+        try:
+            parent_matches_head = repo.head.commit == parent_commit
+        except ValueError:
+            # We are most likely in an empty repository, so the HEAD doesn't point to a valid ref
+            parent_matches_head = True
+        # end
+
         if not repo.bare and parent_matches_head:
             fp_module = os.path.join(repo.working_tree_dir, cls.k_modules_file)
         else:
@@ -370,6 +381,14 @@ def add(cls, repo, name, path, url=None, branch=None, no_checkout=False):
             mrepo = cls._clone_repo(repo, url, path, name, **kwargs)
         # END verify url
 
+        # It's important to add the URL to the parent config, to let `git submodule` know.
+        # otherwise there is a '-' character in front of the submodule listing
+        #  a38efa84daef914e4de58d1905a500d8d14aaf45 mymodule (v0.9.0-1-ga38efa8)
+        # -a38efa84daef914e4de58d1905a500d8d14aaf45 submodules/intermediate/one
+        writer = sm.repo.config_writer()
+        writer.set_value(sm_section(name), 'url', url)
+        writer.release()
+
         # update configuration and index
         index = sm.repo.index
         writer = sm.config_writer(index=index, write=False)
@@ -386,11 +405,23 @@ def add(cls, repo, name, path, url=None, branch=None, no_checkout=False):
         del(writer)
 
         # we deliberatly assume that our head matches our index !
-        pcommit = repo.head.commit
-        sm._parent_commit = pcommit
+        parent_repo_is_empty = False
+        try:
+            sm._parent_commit = repo.head.commit
+        except ValueError:
+            parent_repo_is_empty = True
+            # Can't set this yet, if the parent repo is empty.
+        # end
         sm.binsha = mrepo.head.commit.binsha
         index.add([sm], write=True)
 
+        if parent_repo_is_empty:
+            # The user is expected to make a commit, and this submodule will initialize itself when
+            # _parent_commit is required
+            del sm._parent_commit
+            log.debug("Will not set _parent_commit now as the parent repository has no commit yet.")
+        # end
+
         return sm
 
     def update(self, recursive=False, init=True, to_latest_revision=False, progress=None,
@@ -875,6 +906,49 @@ def config_writer(self, index=None, write=True):
         writer.config._auto_write = write
         return writer
 
+    @unbare_repo
+    def rename(self, new_name):
+        """Rename this submodule
+        :note: This method takes care of renaming the submodule in various places, such as
+
+            * $parent_git_dir/config
+            * $working_tree_dir/.gitmodules
+            * (git >=v1.8.0: move submodule repository to new name)
+
+        As .gitmodules will be changed, you would need to make a commit afterwards. The changed .gitmodules file
+        will already be added to the index
+
+        :return: this submodule instance
+        """
+        if self.name == new_name:
+            return self
+
+        # .git/config
+        pw = self.repo.config_writer()
+        # As we ourselves didn't write anything about submodules into the parent .git/config, we will not require
+        # it to exist, and just ignore missing entries
+        if pw.has_section(sm_section(self.name)):
+            pw.rename_section(sm_section(self.name), sm_section(new_name))
+        # end
+        pw.release()
+
+        # .gitmodules
+        cw = self.config_writer().config
+        cw.rename_section(sm_section(self.name), sm_section(new_name))
+        cw.release()
+
+        self._name = new_name
+
+        # .git/modules
+        mod = self.module()
+        if mod.has_separate_working_tree():
+            module_abspath = self._module_abspath(self.repo, self.path, new_name)
+            os.renames(mod.git_dir, module_abspath)
+            self._write_git_file_and_module_config(mod.working_tree_dir, module_abspath)
+        # end move separate git repository
+
+        return self
+
     #} END edit interface
 
     #{ Query Interface

git/repo/base.py

@@ -868,6 +868,15 @@ def archive(self, ostream, treeish=None, prefix=None, **kwargs):
         self.git.archive(treeish, *path, **kwargs)
         return self
 
+    def has_separate_working_tree(self):
+        """:return: True if our git_dir is not at the root of our working_tree_dir, but a .git file with a
+        platform agnositic symbolic link. Our git_dir will be whereever the .git file points to
+        :note: bare repositories will always return False here
+        """
+        if self.bare:
+            return False
+        return os.path.isfile(os.path.join(self.working_tree_dir, '.git'))
+
     rev_parse = rev_parse
 
     def __repr__(self):

git/test/test_config.py

@@ -193,3 +193,16 @@ def check_test_value(cr, value):
         cr = GitConfigParser(fpa, read_only=True)
         check_test_value(cr, tv)
         cr.release()
+
+    def test_rename(self):
+        file_obj = self._to_memcache(fixture_path('git_config'))
+        cw = GitConfigParser(file_obj, read_only=False, merge_includes=False)
+
+        self.failUnlessRaises(ValueError, cw.rename_section, "doesntexist", "foo")
+        self.failUnlessRaises(ValueError, cw.rename_section, "core", "include")
+
+        nn = "bee"
+        assert cw.rename_section('core', nn) is cw
+        assert not cw.has_section('core')
+        assert len(cw.items(nn)) == 4
+        cw.release()

git/test/test_repo.py

@@ -164,6 +164,7 @@ def test_init(self):
                 r = Repo.init(path=path, bare=True)
                 assert isinstance(r, Repo)
                 assert r.bare is True
+                assert not r.has_separate_working_tree()
                 assert os.path.isdir(r.git_dir)
 
                 self._assert_empty_repo(r)
@@ -200,6 +201,7 @@ def test_init(self):
             os.chdir(git_dir_rela)
             r = Repo.init(bare=False)
             assert r.bare is False
+            assert not r.has_separate_working_tree()
 
             self._assert_empty_repo(r)
         finally:

git/test/test_submodule.py

@@ -670,8 +670,10 @@ def test_git_submodule_compatibility(self, rwdir):
         assert module_repo_path.startswith(os.path.join(parent.working_tree_dir, sm_path))
         if not sm._need_gitfile_submodules(parent.git):
             assert os.path.isdir(module_repo_path)
+            assert not sm.module().has_separate_working_tree()
         else:
             assert os.path.isfile(module_repo_path)
+            assert sm.module().has_separate_working_tree()
             assert find_git_dir(module_repo_path) is not None, "module pointed to by .git file must be valid"
         # end verify submodule 'style'
 
@@ -689,6 +691,8 @@ def test_git_submodule_compatibility(self, rwdir):
         # Fails because there are new commits, compared to the remote we cloned from
         self.failUnlessRaises(InvalidGitRepositoryError, sm.remove, dry_run=True)
 
+        # TODO: rename nested submodule
+
         # remove
         sm_module_path = sm.module().git_dir
 
@@ -698,3 +702,22 @@ def test_git_submodule_compatibility(self, rwdir):
             assert sm.module_exists() == dry_run
             assert os.path.isdir(sm_module_path) == dry_run
         # end for each dry-run mode
+
+    @with_rw_directory
+    def test_rename(self, rwdir):
+        parent = git.Repo.init(os.path.join(rwdir, 'parent'))
+        sm_name = 'mymodules/myname'
+        sm = parent.create_submodule(sm_name, 'submodules/intermediate/one', url=self._submodule_url())
+        parent.index.commit("Added submodule")
+        assert sm._parent_commit is not None
+
+        assert sm.rename(sm_name) is sm and sm.name == sm_name
+
+        new_sm_name = "shortname"
+        assert sm.rename(new_sm_name) is sm
+        assert sm.exists()
+
+        sm_mod = sm.module()
+        if os.path.isfile(os.path.join(sm_mod.working_tree_dir, '.git')) == sm._need_gitfile_submodules(parent.git):
+            assert sm_mod.git_dir.endswith(".git/modules/" + new_sm_name)
+        # end