Allow xref buttons to have "internal" links

still assume external (open in new tab) by default

tailbone/views/master.py

@@ -2644,17 +2644,33 @@ class MasterView(View):
         return normal
 
     def make_xref_button(self, **kwargs):
+        """
+        Make and return a HTML ``<b-button>`` literal, for display in
+        the cross-reference helper panel.
 
+        :param url: URL for the link.
+        :param text: Label for the button.
+        :param internal: Boolean indicating if the link is internal to
+           the site.  This is false by default, meaning the link is
+           assumed to be external, which affects the icon and causes
+           button click to open link in a new tab.
+        """
         # nb. unfortunately HTML.tag() calls its first arg 'tag' and
         # so we can't pass a kwarg with that name...so instead we
         # patch that into place manually
-        button = HTML.tag('b-button', type='is-primary',
-                          href=kwargs['url'], target='_blank',
-                          icon_pack='fas', icon_left='external-link-alt',
-                          c=kwargs['text'])
+        btn_kw = dict(type='is-primary',
+                      href=kwargs['url'],
+                      icon_pack='fas',
+                      c=kwargs['text'])
+        if kwargs.get('internal'):
+            btn_kw['icon_left'] = 'eye'
+        else:
+            btn_kw['icon_left'] = 'external-link-alt'
+            btn_kw['target'] = '_blank'
+        button = HTML.tag('b-button', **btn_kw)
         button = six.text_type(button)
-        button = button.replace('target="_blank"',
-                                'target="_blank" tag="a"')
+        button = button.replace('<b-button ',
+                                '<b-button tag="a"')
         button = HTML.literal(button)
         return button