Bugzilla

There's a few cases I misssed when working on bug 1998199, mostly seem to be with the various callbacks in `#handleTabMove` in tabbrowser.js, where its not checking for whether a tab is within a splitview. This is pretty noticeable in cases like `moveTabTo` when an elementIndex is not passed in, as is the case with sidebar extensions like TST but likely in other scenarios.

There's a few cases I misssed when working on bug 1998199, mostly seem to be with the various callbacks in `#handleTabMove` in tabbrowser.js, where its not checking for whether a tab is within a splitview. This is pretty noticeable in cases like `moveTabTo` when an elementIndex is not passed in, as is the case with sidebar extensions like TST but likely in other scenarios.

This patch also covers `moveTabForward` and `moveTabBackwards` used by keyboard shortcuts; it handles both the movement of tabs within splitviews (discussed with Yulia that we should keep those tabs together and move the entire wrapper) and prevents tabs from being moved into a splitview.