To resume, what can be automated is the database filling. The steps that make the admin copy the files to the web repository, and to create a DB account for mantis cannot be automated through Mantisbt.

What is possible is a single (or few) page(s) to configure DB access (server, user, pass, database name), then fill in the base and set default.

selection of the web repository path can be automated (browse to install path).
db account creation can be assisted/automated as you suggest.

A great script would be to guide the user in setting up all (or a good sub-set) of the options in the config-inc.php file.

Once finished, the script would generate the file, then run the setup SQL statements.

Thus all a user needs to do is upload, unpack, create the DB, and run the script.

Take a look at Moodle (www.moodle.org) for a very well implemented install routine.

Thank you for taking the time to report a problem with mantis.

The newest releases of mantis do have an install.php routine that automatically runs. Please report suggestions/improvements to this new routine.

Since this problem report was originally made, a number of releases have occurred.
It appears that this issue has either been fixed, or may not be a relevant report for the current release.

Unfortunately you are not using the latest version and the problem might already be fixed. Please download the latest release from http://www.mantisbt.org/download.php

If you are able to reproduce this bug in the current release, or have some more information on how this feature could be improved in the current release. Please either change the mantis version on this bug report
to the version you tested and change the status back to "Open", or open a new issue report wit more information.

Again, thank you for your continued support and report.
Paul