bug: make classhelper link open in new window when js is disabled

Prevent the web page displaying a classhelper link from being replaced
if JavaScript is disabled.

Author: rouilj

CHANGES.txt

@@ -148,6 +148,9 @@ Fixed:
 - issue2551350 - Python changes for 3.12 with roundup 2.3.0. Fixes for
   mailer.py crash due to change in starttls signature change. (Patch
   by Andrew (kragacles), modified and applied John Rouillard)
+- make classhelper link open in a new window by setting
+  target="_blank". This prevents overwriting of current page with the
+  classhelper if javascript is disabled. (John Rouillard)
 
 Features:
 

roundup/cgi/templating.py

@@ -981,7 +981,7 @@ def classhelp(self, properties=None, label=''"(list)", width='500',
                   (help_url, width, height)
         return ('<a class="classhelp" data-helpurl="%s" '
                 'data-width="%s" data-height="%s" href="%s" '
-                'onclick="%s" %s>%s</a>') % (
+                'target="_blank" onclick="%s" %s>%s</a>') % (
                     help_url, width, height,
                     help_url, onclick, self.cgi_escape_attrs(**html_kwargs),
                     self._(label))