UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Steps to reproduce the problem:
1. Load a Youtube URL for a video in a playlist
2. Select portion of URL only containing the first GET argument
3. Copy or cut to clipboard (note that, when cutting, only selected portion of URL is cut)
4. Paste in another program, revealing clipboard contents to be whole URL

What is the expected behavior?
Copy/cut in the address bar should only copy the selected region to the clipboard.

What went wrong?
When attempting to copy the video URL for a Youtube video in a playlist, the playlist information (i.e. the GET arguments for it) were included in the paste, even though only the first GET argument (i.e. ?v=...) was selected (along with the scheme, domain, and path portions of the URL). Note that this cutting still behaves as we expect, and that it was not reproduced on other origins' URLs (e.g. hangouts.google.com).

Did this work before? Yes I don't remember what version I had before an automated update recently, but it certainly worked a month ago while I had no pending updates.

Chrome version: 67.0.3396.99  Channel: stable
OS Version: OS X 10.11.4
Flash Version: 

I asked someone at Chromium if this was a new security feature to prevent users from incorrectly mis-copying a URL to as a safeguard from homonym attacks, and was told that it sounded like a regression.