Patch Set 5:

> - I feel the feature that editing the tag name edit field
> filters the list of existing tags is not obvious.
> I first had the impression that something is weird here,
> after playing around I discovered that this is filtering
> and not a bug. IMHO it's a good idea but somehow this
> needs to be made more obvious.

Maybe we should change filter here (now it checks that existing tag name starts with value in 'tag name' input) and maybe add light bulb same as to commit combo to indicate that this field has realtime influence on dialog's content.

> - I think the dialog title should be just
> Create tag on branch "xyz"

DONE.

> - when trying to replace an existing tag I would expect that
> the fields switch to read-only automatically when the tag
> name field is equal to an existing tag name, having to
> select the existing tag for that requires too many clicks
> and doesn't feel intuitive

Lets consider situation when this feature is implemented and user want to create tag 'v1.0.1' when he had already existing tag 'v1.0'.
In this case he will type 'v1.0' in tag name field, then all fields goes read-only and he must check 'Force replace existing tag' to be able to continue typing. This behavior would be very confusing and counterproductive.
I have negative filings about this feature.

> - I was not able to actually replace an existing tag since
> there seems to be no way to enable the OK button when the
> force checkbox is checked

I'll check that.