Improperly shaped dialog when there are not affirmative or dismissive buttons

[EanLombardo]

If you have no affirmative or dismissive buttons in your dialog, the dialog still shows space at the bottom where affirmative or dismissive buttons would be. The dialog shows up taller than it needs to be.

Because only affirmative or dismissive buttons show up in this space, if you are using your own button that handles dialog dismissal under it's own rules, the extra space shows beneath the button and the whole dialog looks wrong.

[morethanreal]

This should be fixed. paper-dialog does not have special handling for buttons. The new paper-action-dialog should be used if you want buttons.