Open Radar

 
Summary:
Preview cannot scroll correctly on the thumbnail view with landscape PDFs.

I have a 100+ page landscape PDF that was generated using Keynote (Standard 4:3 size).

The scrolling on the thumbnails using a 2-finger gesture is impossible with a landscape PDF.

The scrollbar is buggy and shows a single page, or erratically jumps to show the correct position.

The scroll location keeps reseting to the bottom. This makes it impossible to scroll through thumbnails.

Sidenote: scrolling with a thumbwheel logitech USB mouse works ok in the thumbnail, but the scrollbar still renders it's size erratically.

Steps to Reproduce:
1. Open Test2LandscapeBUGGY.pdf in Preview
2. Open sidebar
3. Scroll with 2-finger gesture on the Thumbnails

Expected Results:

1. I should be able to move to any location

Actual Results:

1. The scroll location resets to the bottom of the PDF (last page) and resumes the gesture scroll momentum. It is impossible to scroll.

Regression:
This does not occur with landscape PDFS

Notes:
Provide additional information, such as references to related problems, workarounds and relevant attachments.