Do not show badge for master only repos

If a repo has no stable branches, we do not need to show the badge,
disable it automatically.

Also, disable it for releasenotes, api-guide and api-ref. These
documents are always published from master and are versionless.

This avoids changing most of the repositories to disable the badge.

Change-Id: I063af45e40bd41e27334638e2cf65ca0c9119e63

doc/source/index.rst

@@ -140,8 +140,10 @@ with documentation available. By default it is set to ``None``::
     document with internal versioning.
 
 
-By default, a badge is displayed showing which the latest OpenStack
-release is. You can disable the badge with::
+A badge pointing out the support status of a document is shown now
+for repositories that have ``stable/`` branches. The badge is not
+displayed for api-ref, api-guide and releasenotes documents. It
+can be disabled with the ``display_badge`` html theme option::
 
         html_theme_options = {
         # ...

openstackdocstheme/ext.py

@@ -34,6 +34,21 @@ _html_context_data = None
 logger = logging.getLogger(__name__)
 
 
+def _has_stable_branches():
+    try:
+        repo = dulwich.repo.Repo.discover()
+    except dulwich.repo.NotGitRepository:
+        return False
+
+    refs = repo.get_refs()
+    for ref in refs.keys():
+        ref = ref.decode('utf-8')
+        if ref.startswith('refs/remotes/origin/stable'):
+            return True
+
+    return False
+
+
 def _get_other_versions(app):
     if not app.config.html_theme_options.get('show_other_versions', False):
         return []
@@ -117,6 +132,21 @@ def _html_page_context(app, pagename, templatename, context, doctree):
             _html_context_data['bug_tag'] = bug_tag
         _html_context_data['series'] = _get_series_name()
 
+        # Do not show the badge in these cases:
+        # - display_badge is false
+        # - repo has no stable/ branches
+        # - directory is named api-guide, api-ref, or releasenotes
+        if not app.config.html_theme_options.get('display_badge', True):
+            _html_context_data['display_badge'] = False
+        elif _has_stable_branches():
+            doc_parts = os.path.abspath(app.srcdir).split(os.sep)[-2:]
+            if doc_parts[0] in ('api-guide', 'api-ref', 'releasenotes'):
+                _html_context_data['display_badge'] = False
+            else:
+                _html_context_data['display_badge'] = True
+        else:
+            _html_context_data['display_badge'] = False
+
     context.update(_html_context_data)
     context['other_versions'] = _get_other_versions(app)
 

openstackdocstheme/theme/openstackdocs/layout.html

@@ -94,7 +94,7 @@ ga('send', 'pageview');
 {% include 'footer.html' %}
 {% include 'script_footer.html' %}
 {% block script_footer %}{% endblock %}
-{% if theme_display_badge %}
+{% if display_badge %}
 <script type="text/javascript">
     $(document).ready(function(){
 

releasenotes/notes/badge-6f8713da36a7e570.yaml

@@ -0,0 +1,7 @@
+features:
+  - |
+    A badge pointing out the support status of a document is shown now
+    for repositories that have ``stable/`` branches. The badge is not
+    displayed for api-ref, api-guide and releasenotes documents. It
+    can be disabled with the ``display_badge`` html theme option.
+