Il Filosofo

Today while developing a WordPress theme for a client, I ran into a vexing Internet Explorer 7 bug. Anyone who’s done any website design is familiar with Internet Explorer 6 (or earlier) wreaking havoc with standards-compliant work that looks good in, say, Firefox. But thankfully IE 7 has for the most part been a big improvement over its predecessor. That’s what made this bug so strange: it didn’t affect IE 6, just IE 7.

The first image shows a screenshot of the problem: the title of the post is drooping into the post. Usually when you see something like this, it means that the containing element has not been cleared. There are a number of ways to clear an element: a popular fix these days uses a pseudo class; the classic approach has been to put a cleared element within the same element as the floating element, but after it. Neither fix works for this bug.

Thankfully, I found a demonstration of a similar problem with IE 7. Apparently if the element containing the floating element has a set height or a maximum height, it confuses IE 7. According to the standard, a browser should obey the CSS height of the element (and IE 7 does—good job!—unlike IE 6). But every cleared element after the floater should be pushed down, not overlapped, by the floater.

The solution is to remove the height assignment from the container element, if you can. In my case, for another part of the site experiencing the same problem, I needed the element to have enough height to show a background image. The solution was to use the min-height property, which doesn’t trigger the bug.

The final image shows what it should look like, as rendered by Firefox.