Currently there is no way to reference multiple lines, other than the line numbers (which I understand is crude, but can be effective). As Dylan mentions, this isn't an oversight so much as a conscious decision, one that we knew had both pros and cons.
In terms of usability, the fact that developers are actually using the line commenting feature as is — seeing the code review comment appear near the code it applies to — already shows that most developers actually prefer to be specific about the context of their comment.
How many Bitbucket users refrain from using line comments, and instead place their review comments straight underneath the pull-request description? I wonder…
This feature request is nothing more than an improvement of a feature that has already been proven to be very important to the review process.
I too would like to add my +1 on this feature request. Is a shame for bitbucket to lag behind gerrit and github in this regard. In fact if you guys could implement it so that the lines don't have to be contiguous you would have an advantage over the other 2 (I think, been a while since I used Gerrit)
I would love this too. We use crucible at work, and this feature is invaluable.
The argument I heard against it was that if you just want to select text so you can copy it, then the comment editor is invoked when you didn't want it. But couldn't comment line selection be done with a modifier key? i.e. shift-click/drag if you want to comment. Without shift, it's just normal selection behaviour.
Having previously used Crucible at another studio, I was surprised that the same functionality wasn't available from Atlassian in BitBucket (used by my new employer). This feature would be highly useful for our code reviews.
Multi-line comments are essential. Single line comments are fine for trivial stuff like typos be real coding and logic defects almost always span multiple lines. Highlighting on the UI would be nice but if you really feel such a useful feature confuses the UI at least consider auto-filling the first line of the comment box with "lines: xxx-yyy" when the user marks a multi-line selection.
Same as everyone else here, I would definitely use the multi-line feature every single day. It's especially useful when you get an email with comments. You only see one line in the email. It's confusing.