src/sage/doctest/control.py: Fixup handling of sage_optional_tags

src/sage/doctest/control.py

@@ -40,7 +40,7 @@
 from .external import external_software, available_software
 
 nodoctest_regex = re.compile(r'\s*(#+|%+|r"+|"+|\.\.)\s*nodoctest')
-optionaltag_regex = re.compile(r'^\w+$')
+optionaltag_regex = re.compile(r'^(\w|[.])+$')
 
 # Optional tags which are always automatically added
 
@@ -53,9 +53,6 @@
 except ImportError:
     pass
 
-from sage.features.sagemath import sage_optional_tags
-auto_optional_tags.update(sage_optional_tags())
-
 class DocTestDefaults(SageObject):
     """
     This class is used for doctesting the Sage doctest module.
@@ -374,6 +371,9 @@ def __init__(self, options, args):
                     from sage.features import package_systems
                     options.optional.update(system.name for system in package_systems())
 
+                    from sage.features.sagemath import sage_optional_tags
+                    options.optional.update(sage_optional_tags())
+
                 # Check that all tags are valid
                 for o in options.optional:
                     if not optionaltag_regex.search(o):