Added rendering for submodules

docs/getting-started.rst

@@ -30,6 +30,13 @@ underscore)::
 
     extensions = ['sphinx_git']
 
+There is one global switch that changes the behavior of sphinx-git when
+processing git submodules. Default behavior is that sphing-git renders
+the git history of the sphinx directory. If you want sphinx-git to
+render the history of the submodule instead you can add::
+
+    git_respect_submodules = True
+
 Add A git Changelog To Your Project
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -58,4 +65,4 @@ was compiled with the ``git_commit_detail`` directive::
 
     .. git_commit_detail::
         :branch:
-        :commit:
+        :commit:

sphinx_git/__init__.py

@@ -21,14 +21,17 @@
 from docutils.parsers.rst import directives
 from git import Repo
 from sphinx.util.compat import Directive
-
+from os import path
 
 # pylint: disable=too-few-public-methods, abstract-method
 class GitDirectiveBase(Directive):
     def _find_repo(self):
         env = self.state.document.settings.env
-        repo = Repo(env.srcdir, search_parent_directories=True)
-        return repo
+        if env.config.git_respect_submodules:
+            srcdir = path.dirname(env.doc2path(env.docname, base=True))
+        else:
+            srcdir = env.srcdir
+        return Repo(srcdir, search_parent_directories=True)
 
 
 # pylint: disable=too-few-public-methods
@@ -195,3 +198,4 @@ def _build_markup(self, commits):
 def setup(app):
     app.add_directive('git_changelog', GitChangelog)
     app.add_directive('git_commit_detail', GitCommitDetail)
+    app.add_config_value('git_respect_submodules', False, 'env')