Open Radar

 
Summary:
When scrolling inside a file, like a text document, the scroll bar box transparency glitches out.  This glitch also occurs when one scrolls inside a Quick Viewed document that doesn’t even have a scroll bar.

Steps to Reproduce:
1. Quick View a text file.
2. Scroll down in the text file without using the scroll bar.

Expected Results:
If the file doesn't have overflowing contents that would require a scroll bar, there should be no transparency changes.  If the file does have overflowing contents requiring a scroll bar, the transparency should only appear if one is hovering over the scroll bar.  OS X Mavericks 10.9.5 has the correct scroll bar behavior.

Actual Results:
When scrolling inside a file, like a text document, the scroll bar box transparency glitches out.  This glitch also occurs when one scrolls inside a Quick Viewed document that doesn’t even have a scroll bar.

Version:
OS X El Capitan

Notes:
NONE

Configuration:
This bug occurs on every version of El Capitan regardless of hardware configurations.

Attachments:
NONE