[editing] When should UA synthesize heights of an element? (#70)

Currently, Blink and WebKit synthesize heights of elements under certain conditions. Without this, since CSS defines an empty element has zero-height, you can't place a caret inside of an empty element (or logically you can, but it can't be visible because the height is zero.) See [this example](http://jsbin.com/bupeme/edit?html,output). A `div` gets the height of `line-height` if CE.

Blink and WebKit today disallows to set carets to where height=0. With CE=events, JS can set carets to anywhere, but without synthesizing heights, it won't be visible.

The example above is simple, but it gets more complicated if the `div` has empty children, or replaced elements of height=0.

Maybe related with #68?

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/editing/issues/70