UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36

Steps to reproduce the problem:
1. visit https://css-tricks.com/snippets/css/a-guide-to-flexbox/
2. press CTRL+F
3. type in "width"
4. click on the beggining of the page, for example on the gray area above the title "A Complete Guide to Flexbox"
5. click several times on the up "^" arrow in the search box

What is the expected behavior?
The index of the match should be always a positive number.
I would expect something like:
"1 z 87"
"87 z 87"
"86 z 87"
"85 z 87"

What went wrong?
While pressing the up arrow, the sequence observed in the GUI is:
"1 z 87"
"87 z 87"
"87 z 87"
"-2 z 87"

Did this work before? N/A 

Chrome version: 50.0.2661.102  Channel: n/a
OS Version: 10.0
Flash Version: Shockwave Flash 21.0 r0

I think this might be caused by dynamic DOM generation/infinite scroll/ajax, but I am not sure, and do not know how to provide a minimal repro for this.
 

Deleted: negative_index.png 349 KB

	negative_index.png 349 KB View Download