software/theia: public folder is not public in Theia

This is a fixup of 665166e2 (see
especially nexedi/slapos@665166e2 (comment 177402))

software/theia/buildout.hash.cfg

@@ -15,7 +15,7 @@
 
 [instance-theia]
 _update_hash_filename_ = instance-theia.cfg.jinja.in
-md5sum = 4b69822605e3f20fcec8f44a0bdf80bb
+md5sum = 8a6efc1054b60f3cbd114a9f6097bae5
 
 [instance]
 _update_hash_filename_ = instance.cfg.in

software/theia/instance-theia.cfg.jinja.in

@@ -261,14 +261,13 @@ content =
     log global
     bind $${:ip}:$${:port} ssl crt $${frontend-instance-certificate:cert-file} alpn h2,http/1.1
     # writing twice the same ACL is doing OR
-    acl is_public path_beg /public/
     acl is_public path /$${frontend-instance-favicon.ico:filename}
     acl is_public path /$${frontend-instance-theia.webmanifest:filename}
     acl is_public path /$${frontend-instance-theia-serviceworker.js:filename}
     acl auth_ok http_auth(basic-auth-list)
-    # No authentication for public folder
+    # No authentication for some files
     http-request auth unless auth_ok || is_public
-    use_backend static if { path_beg /$${frontend-instance-fonts:folder-name} } || { path_beg /$${frontend-instance-slapos.css:folder-name} } || { path /$${frontend-instance-logo:filename} } || is_public
+    use_backend static if { path_beg /$${frontend-instance-fonts:folder-name} } || { path_beg /$${frontend-instance-slapos.css:folder-name} } || { path /$${frontend-instance-logo:filename} } || { path_beg /public/ } || is_public
     default_backend nodejs
 
   backend nodejs

software/theia/test/test.py

@@ -146,14 +146,16 @@ class TestTheia(TheiaTestCase):
         )).geturl()
     self.get(authenticated_url)
 
-    # there's a public folder to serve file (no need for authentication)
+    # there's a public folder to serve file
     with open('{}/srv/frontend-static/public/test_file'.format(
         self.getPath()), 'w') as f:
       f.write("hello")
-    resp = self.get(urljoin(url, '/public/'))
+    resp = self.get(urljoin(authenticated_url, '/public/'))
     self.assertIn('test_file', resp.text)
-    resp = self.get(urljoin(url, '/public/test_file'))
+    resp = self.get(urljoin(authenticated_url, '/public/test_file'))
     self.assertEqual('hello', resp.text)
+    # make sure public folder is protected
+    resp = self.get(urljoin(url, '/public/test_file'), requests.codes.unauthorized)
 
     # there's a (not empty) favicon (no need for authentication)
     resp = self.get(urljoin(url, '/favicon.ico'))