Bug 102504

When applying Text Autosizing to blocks of text with a fixed-height background image, it's common for the text to wrap and exceed the height of the background image. For example on above Flickr url, they have made custom numbered list markers like: <style> li > .num { color: #fff; /* tour_blue-circle.png is an 18x18 blue bullet */ background: url(http://l.yimg.com/g/images/tour/tour_blue-circle.png) no-repeat; } </style> <li><span class="num">2</span> (text goes here...) </li> This is perfectly reasonable, but Text Autosizing ends up making the number spill out of the blue circle, and since the number and page background are both white this means it disappears! We need to fix this category of bugs in one of two ways: 1. Skip blocks with fixed-height background images, when deciding what to autosize. 2. Scale fixed-height background images up in proportion to the text size multiplier (or even better, take wrapping into account to work out the exact height gain due to Text Autosizing). As a short/medium-term fix, I recommend going with option 1. Once that's in place we can investigate option 2 (with lower priority). For option 1, the main thing we need to decide is what should count as a fixed height background image: for example a block with its vertical background-size set to "contain", "cover" or a percentage value should not count as fixed. It's less clear whether a block with its vertical background-repeat set to "repeat" should count as flexible height (especially since the default value is "repeat", and so if designers don't expect the contents to exceed the size of the background image they will often leave it as its default value despite not wanting the background to repeat). As a starting point style->hasBackgroundImage() can tell us which blocks have background images :)