There's an 'off-by-1' error in platform/graphics/chromium/FontCacheChromium.cpp. As a result, when only the last font in the list of fallback fonts covers a character, the character is regarded as not covered by any font and is rendered as an empty box.
Created attachment 27426 [details] a test case With code2000 font installed, all 3 lines should be rendered identically.
Created attachment 27429 [details] 1-liner patch (with a comment)
Comment on attachment 27429 [details] 1-liner patch (with a comment) OK. In the future, you don't need to make me the requestee. WebKit doesn't tend to target reviews to specific people unless you know that they are the only person who could review your change. In this case, I'm not the only person who could review this change. Making me the requestee is likely to just slow down the process.
Landed as http://trac.webkit.org/changeset/41392.