scrolling while zoomed in using double tap moves background

Originator:BLoerwald
Number:rdar://12167614 Date Originated:24-Aug-2012 12:44 PM
Status:Open Resolved:
Product:Safari Product Version:6.0 (8536.25)
Classification:Other Bug Reproducible:Always
 
Summary: When having an position-fixed background and double-tapping some text to zoom in, then scrolling down, the background moves down as well, but faster than the viewport, therefore showing whitespace after some time, instead of the fixed position background.

Steps to Reproduce:
1. Go to / make a site having a background set with background-attachment: fixed;. (like http://lancearmstrong.com, there is a background set like that for <html>).
2. double tap some element to zoom in on it.
3. scroll down.

Expected Results: The background keeps being fixed at the position it was earlier, but zoomed in.

Actual Results: The background moves when double tapping and even more when scrolling.

Comments

While this does break certain types of pages, I'm convinced this is intentional. Try it on, for instance, lionhead.com, and observe how the background moves just enough that you get to see the top and bottom of it where they're supposed to be.

By nivi at Sept. 3, 2012, 8:35 a.m. (reply...)

Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!