I am blind and use VoiceOver. On both Mac OS and IOS Safari renders many icons in a frequently used web site as "index.php". On Mac OS Chrome renders sensible text for these icons. Investigation shows that Chrome gets its text from TITLE tags associated with the icons, as the ALTTXT tags for these icons are null or missing or blank. On IOS Chrome behaves the same as Safari.
can you give an example.
We do use title as the final fallback for many cases
Bug 173870 describes an example of how to create this bug. You can close bug 173006 as bug 173870 supercedes bug 173006.