Next time you'll backup your database first, eh?;)
As said previously, it's probably not a great idea to modify core themes.
But anyway, I just tested your scenario and can't reproduce it.
Here's what I did: copied the Garland theme to sites/all/themes/test moved garland.info to test.info replaced all instances of the word "garland" with "test" in theme-settings.php, template.php and test.info
Importantly (I think) I commented out the line "package = Core" in test.info. ;D
Changed the theme to test and everything is working fine.
I highly recommend you have a look at Sky and Corolla, which are sub-themes of Adaptivetheme. There's even a sub-sub-theme called Footheme, with which you can override the CSS and keep your changes separate and organised.
That could be considered top-heavy, I guess, but it's worth it for the time saving, and mobile-ready layout, amongst many other nifty features. And it's especially great for someone like me, who is more a content provider and sysadmin than developer. (My grasp of CSS is tenuous at best.)
HTH
On Wed, 2011-10-05 at 16:16 +1100, Roger wrote:
Copying a drupal default theme to /sites/all/themes/ and rework the .info, template.php and theme-settings.php as per tutorial and all works
- until!
Until one insert as the line base theme = garland or base theme = new name into the .info file of the new renamed .info. Bingo drupal is dead, no access to the system because there's no theme.
It does not default to (Seven) the admin theme. Most peculiar that drupal can eliminate access because of a line in the .info file. If the offending line is commented out, deleted or changed to garland, drupal still dead.
It seems that drupal reads the multi site .info once and saves a change to somewhere in the database then does not re read the .info file To fix: Needs a fresh install of that particular multi site.
So if someone changes the .info file it kills drupal 7! This needs serious attention. It is inconceivable that something as innocuous as the .info file can be so destructive.
Cheers Roger