Fix fail to load template file if the parent template is archived

CHANGES

@@ -117,6 +117,7 @@ Bugs fixed
 * C++, properly look up ``any`` references.
 * #3624: sphinx.ext.intersphinx couldn't load inventories compressed with gzip
 * #3551: PDF information dictionary is lacking author and title data
+* Fail to load template file if the parent template is archived
 
 Deprecated
 ----------

sphinx/jinja2glue.py

@@ -135,8 +135,8 @@ class BuiltinTemplateLoader(TemplateBridge, BaseLoader):
         if theme:
             # the theme's own dir and its bases' dirs
             pathchain = theme.get_dirchain()
-            # then the theme parent paths
+            # the loader dirs: pathchain + the parent directories for all themes
-            loaderchain = pathchain + theme.themepath
+            loaderchain = pathchain + [path.join(p, '..') for p in pathchain]
         elif dirs:
             pathchain = list(dirs)
             loaderchain = list(dirs)

sphinx/theming.py

@@ -22,6 +22,7 @@ from six.moves import configparser
 from sphinx import package_dir
 from sphinx.errors import ThemeError
 from sphinx.util import logging
+from sphinx.util.osutil import ensuredir
 
 logger = logging.getLogger(__name__)
 
@@ -127,12 +128,15 @@ class Theme(object):
         tdir, tinfo = self.themes[name]
         if tinfo is None:
             # already a directory, do nothing
+            self.rootdir = None
             self.themedir = tdir
             self.themedir_created = False
         else:
             # extract the theme to a temp directory
-            self.themedir = tempfile.mkdtemp('sxt')
+            self.rootdir = tempfile.mkdtemp('sxt')
+            self.themedir = path.join(self.rootdir, name)
             self.themedir_created = True
+            ensuredir(self.themedir)
             for name in tinfo.namelist():
                 if name.endswith('/'):
                     continue
@@ -214,7 +218,7 @@ class Theme(object):
         """Remove temporary directories."""
         if self.themedir_created:
             try:
-                shutil.rmtree(self.themedir)
+                shutil.rmtree(self.rootdir)
             except Exception:
                 pass
         if self.base:

tests/roots/test-theming/conf.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 html_theme = 'test-theme'
+html_theme_path = ['.', 'test_theme']
 master_doc = 'index'
 exclude_patterns = ['_build']
 

tests/test_theming.py

@@ -100,3 +100,9 @@ def test_double_inheriting_theme(make_app, app_params):
     with mock.patch('sphinx.theming.load_theme_plugins', side_effect=load_themes):
         args, kwargs = app_params
         make_app(*args, **kwargs)
+
+
+@pytest.mark.sphinx(testroot='theming',
+                    confoverrides={'html_theme': 'child'})
+def test_nested_zipped_theme(app, status, warning):
+    app.build()  # => not raises TemplateNotFound