Automatically Fill Values is so "close" to Format from Other Fields, and countless times I have typed a suitable "Source" only to click "OK" and imagine that it would populate the field I intended to (but alas, forgot to fill in).
Couldn't the "OK" be greyed out and inaccessible as long as "Pattern" is empty?
It is easy to exit the dialogue by Cancel.
I second this, just like I second any fool-proof improvements.
OK, changed for the next update, thanks for pointing this out.