pam_winbind upn to username conversion doesn't work if you have defined a different seperator in the config file. It always uses '\'. The following patch will fix the problem.
Created attachment 8673 [details] v3-6-test and v4-0-test patch
Comment on attachment 8673 [details] v3-6-test and v4-0-test patch Looks good, thanks!
Karolin, please add to 4.0.x and 3.6.x. Thanks.
Pushed to v3-6-test and autobuild-v4-0-test.
Pushed to v4-0-test. Closing out bug report. Thanks!