I had a good working new installation of Bugzilla 4.0.
I have upgraded to version 4.0.2 using the patch.
Everything went ok until I had to clear the shutdownhtml field in the Params page
Doing that, gave the error on the screen:
Software error: Error reading ./data/params: Permission denied at Bugzilla/Config.pm line 323. Compilation failed in require at /var/www/bugzilla/editparams.cgi line 28. BEGIN failed--compilation aborted at /var/www/bugzilla/editparams.cgi line 28. For help, please send mail to the webmaster (webmaster@localhost), giving this error message and the time and date of the error.
Ok, it's definitely a permission error. I have set /var/www/bugzilla as follow:
drwxr-xr-x 16 www-data www-data 4096 2011-09-22 12:58 bugzilla/
Q1: What user should have done the patch upgrade? I used Administrator with sudo. -- was that wrong? Q2: What should be the settings for the directory structure and files? isn't 755 and chown/chgrp www-data is enough?
ANSWER: I had to change the following directory in order to fix the permission rights
chmod 777 /var/www/bugzilla/data/template/template/en/default (for all changes to be written) chmod 777 /var/www/bugzilla/data/params
This works, but still I don't know how it happened.