Created attachment 155335 [details]
Update to use correct version of patch for htdig
The update to Mailman 2.1.19 has broken the HTDIG option. This patch applies a combined index and htdig patch from Mark Sapiro for 2.1.19, and updates the distinfo. I've tested it on our Mailman installation, and it's working fine.
A commit references this bug:
Date: Thu Apr 9 20:08:51 UTC 2015
New revision: 383674
Update to new upstream release 2.1.20.
Fixes one security bug , a few other bugs, and adds a feature so that
list admins can edit list addresses.
Uses newer Mailman-and-HTDig integration patches. 
Security: CVE-2015-2775 
Security: a5f160fa-deee-11e4-99f8-080027ef73ec 
PR: 199286 
Submitted by: David Sieb?rger 
I have revised your update to use the 2.1.20 patches instead, now necessary due to the security fix in that release.