If a iframe has a height of 32,768px or greater (INT_MAX + 1), then the iframe does not display in the correct location on the page. This does not happen with other blocks. It seems like an integer overflow problem and could be related to iframes being NSViews on Mac. I am not sure what happens on Windows. Firefox does not have a problem either. See the attached test case.
This was found in the Web inspector, since we use iframes to display resource source code. We want to have the frame be the full height of the document, so we set the height to match the size of the frame body. This lets us put other sibling content (http headers) above the frame and have one scrollbar contain the extra content and the frame.
Created attachment 21845 [details]
Comment on attachment 21845 [details]
On Windows I see a large block of red, with a large block of green beneath it.
I meant to say SHORT_MAX + 1, not INT_MAX.
So it seems this is a cross platform issue.
Created attachment 21852 [details]
Comment on attachment 21852 [details]
Landed in r34693.