Rendering Broken 0px Images Quirk

crbug.com/644802: Render alt text per html5 spec

Different dimensions

Different dimensions, no alt text

Different dimensions, no alt text, src = ""

Different dimensions, no alt text, no src

Different dimensions, alt text, src = ""

1. !alt text
2. !alt text
3. !alt text

Different dimensions, alt text, no src

1. !alt text
2. !alt text
3. !alt text
4. !alt text

Different dimensions, alt text, src =

1. !alt text
2. !alt text
3. !alt text