change "epub_show_urls" option default value to 'inline'.

This keeps the current behaviour.

doc/config.rst

@@ -939,11 +939,12 @@ the `Dublin Core metadata <http://dublincore.org/>`_.
 
 .. confval:: epub_show_urls
 
-   Control whether to display URL addresses.  This is very useful for printed
-   copies of the manual.  The setting can have the following values:
+   Control whether to display URL addresses. This is very useful for
+   readers that have no other means to display the linked URL. The
+   settings can have the following values:
 
-   * ``'no'`` -- do not display URLs (default)
-   * ``'inline'`` -- display URLs inline in parentheses
+   * ``'inline'`` -- display URLs inline in parentheses (default)
+   * ``'no'`` -- do not display URLs
 
 
 .. _latex-options:

sphinx/builders/epub.py

@@ -283,7 +283,7 @@ class EpubBuilder(StandaloneHTMLBuilder):
 
     def add_visible_links(self, tree, show_urls='no'):
         """Append visible link targets after external links"""
-        if not show_urls or show_urls == 'no':
+        if show_urls == 'no':
             return
 
         for node in tree.traverse(nodes.reference):

sphinx/config.py

@@ -142,7 +142,7 @@ class Config(object):
         epub_tocdup = (True, 'env'),
         epub_fix_images = (False, 'env'),
         epub_max_image_width = (0, 'env'),
-        epub_show_urls = ('no', None),
+        epub_show_urls = ('inline', None),
 
         # LaTeX options
         latex_documents = (lambda self: [(self.master_doc,