What steps will reproduce the problem?
(1) Create some console message with text (e.g. console.log('foo'))
(2) Create some console message with an expand triangle and text (e.g. type 'xyzzy' and then enter)
(3) Click and drag from the first message (inside 'foo') and mouseup on the expand triangle in the error message below it
(4) Copy / paste the text somewhere

What is the expected result?
Only the selected text in the first message 'foo' should be pasted

What happens instead?
Paste includes all of the text from the second message 'VM112:1 Uncaught ReferenceError: xyzzy is not defined
    at <anonymous>:1:1
(anonymous) @ VM112:1'

Our custom copy handler seems to run into an issue when getSelection() gives us an anchor/focus node that is an Element without textContent.