1325059 - Enforce non-overlapping ranges in Selection harder

Status: NEW

(Core :: DOM: Selection, defect, P3)

Description

[Mats Palmgren (inactive)]

Bug 348681 implemented code to make sure the ranges inside a Selection
are non-overlapping.  It appears to only work for addRange() though,
and things that goes through that same code (Selection::AddItem)
like adding a new range by ctrl+drag.

It appears we don't enforce the invariant when /extending/ an
existing range (by calling setStart/End etc).  I think we should
try to do that since it simplifies editor code (and user script!)
if it doesn't have to deal with overlapping ranges.

Comment 1

[(no longer active)]

Another possible scenario to think about here is the case where the editor code itself creates overlapping range selections by modifying one of the ranges in the selection without caring about the rest of the ranges.  I'm not sure how many of those bugs we still have lying around, but it's worth double checking if someone fixes this.