3 files changed, 30 insertions, 38 deletions
diff --git a/markdown/extensions/extra.py b/markdown/extensions/extra.py
index 19b9db0..e498a74 100644
--- a/markdown/extensions/extra.py
+++ b/markdown/extensions/extra.py
@@ -37,7 +37,6 @@ from .. import util
 import re
 
 extensions = [
-    'smart_strong',
     'fenced_code',
     'footnotes',
     'attr_list',
diff --git a/markdown/extensions/legacy_em.py b/markdown/extensions/legacy_em.py
new file mode 100644
index 0000000..5cc0f6d
--- /dev/null
+++ b/markdown/extensions/legacy_em.py
@@ -0,0 +1,30 @@
+'''
+Legacy Em Extension for Python-Markdown
+=======================================
+
+This extention provides legacy behavior for _connected_words_.
+
+Copyright 2015-2018 The Python Markdown Project
+
+License: [BSD](http://www.opensource.org/licenses/bsd-license.php)
+
+'''
+
+from __future__ import absolute_import
+from __future__ import unicode_literals
+from . import Extension
+from ..inlinepatterns import SimpleTagInlineProcessor
+
+EMPHASIS_RE = r'(\*|_)(.+?)\1'
+STRONG_RE = r'(\*{2}|_{2})(.+?)\1'
+
+
+class LegacyEmExtension(Extension):
+    """ Add legacy_em extension to Markdown class."""
+
+    def extendMarkdown(self, md, md_globals):
+        """ Modify inline patterns. """
+        md.inlinePatterns.register(SimpleTagInlineProcessor(STRONG_RE, 'strong'), 'strong', 40)
+        md.inlinePatterns.register(SimpleTagInlineProcessor(EMPHASIS_RE, 'em'), 'emphasis', 30)
+        md.inlinePatterns.deregister('strong2')
+        md.inlinePatterns.deregister('emphasis2')
diff --git a/markdown/extensions/smart_strong.py b/markdown/extensions/smart_strong.py
deleted file mode 100644
index e7a15d9..0000000
--- a/markdown/extensions/smart_strong.py
+++ /dev/null
@@ -1,37 +0,0 @@
-'''
-Smart_Strong Extension for Python-Markdown
-==========================================
-
-This extension adds smarter handling of double underscores within words.
-
-See <https://Python-Markdown.github.io/extensions/smart_strong>
-for documentation.
-
-Original code Copyright 2011 [Waylan Limberg](http://achinghead.com)
-
-All changes Copyright 2011-2014 The Python Markdown Project
-
-License: [BSD](http://www.opensource.org/licenses/bsd-license.php)
-
-'''
-
-from __future__ import absolute_import
-from __future__ import unicode_literals
-from . import Extension
-from ..inlinepatterns import SimpleTagInlineProcessor
-
-SMART_STRONG_RE = r'(?<!\w)(_{2})(?!_)(.+?)(?<!_)\1(?!\w)'
-STRONG_RE = r'(\*{2})(.+?)\1'
-
-
-class SmartEmphasisExtension(Extension):
-    """ Add smart_emphasis extension to Markdown class."""
-
-    def extendMarkdown(self, md, md_globals):
-        """ Modify inline patterns. """
-        md.inlinePatterns.register(SimpleTagInlineProcessor(STRONG_RE, 'strong'), 'strong', 40)
-        md.inlinePatterns.register(SimpleTagInlineProcessor(SMART_STRONG_RE, 'strong'), 'strong2', 10)
-
-
-def makeExtension(**kwargs):  # pragma: no cover
-    return SmartEmphasisExtension(**kwargs)