3748: Unable to isolate individual lines for review if first line already has a multi-line review

sunxp*****@gmai***** (Google Code) (Is this you? Claim this profile.)
What version are you running?
2.0.13 alpha 0

What's the URL of the page containing the problem?
https://reviews.reviewboard.org/r/6806/diff/4/?file=66249#

What steps will reproduce the problem?
From the URL of the page:
1. Select line 21 and comment for review.
2. Edit your review.

To reproduce from scratch:
1. Select multiple lines on code for any review and publish.
2. Select it again, but this time attempt to select just the first line, and comment.
3. Edit your review.

What is the expected output? What do you see instead?
Users should be able to review and comment on a single line of the code. The same multi-line review comment was selected instead.

What operating system are you using? What browser?
OS X 10.10.1, Chrome 40.0.2214.93

Please provide any additional information below.