Hi Thorsten, Thank you for reporting this issue. I've also encountered this case when upgrading tomcat7 and I agree this is rather annoying.
However I'm not sure to know what should be done here. I was under the impression this dialog was actually expected when a package updates a modified configuration file. The Policy ยง10.7.3 states (about configuration files handled by maintainer scripts): "...it is the responsibility of the package maintainer to provide maintainer scripts which correctly create, update and maintain the file and remove it on purge. [...] These scripts must be idempotent [...], must cope with all the variety of ways dpkg can call maintainer scripts, must not overwrite or otherwise mangle the user's configuration without asking" So I'm tempted to think that asking if the file should be overwritten or not is actually compliant with the policy. What behavior would you expect in this situation? Ignoring the update? Merging the changes? (ucf has a --three-way option to allow merging the changes, I don't know if it would help here). Emmanuel Bourg
