[Bug] Unable to drag tab from tab bar into TST panel

[bossanovaorca]

Abstract

I am not sure if this is a regression or if this behavior was ever supported, but I am not able to drag tabs from the normal tab bar into TST or vice versa. I noticed this alongside #3757 but I'm not sure if the issues are related.

Steps to reproduce

1. Start Firefox with clean profile.
2. Install TST.
3. open two browser windows
4. attempt to drag a tab from the tab bar of one window to the TST side pane of another window

Expected result

I believe the tabs should be moved from one window to the other

Actual result

nothing occurs

Environment

• Platform (OS): Windows 10, macOS
• Version of Firefox: nightly 141.0a1
• Version (or revision) of Tree Style Tab: 4.2.2

[piroor]

Currently the operation works only on some limited situations: when you don't have another tab with same URL, due to restrictions of WebExtensions addons. Drag-and-drop of the native tab prepares a drag data referring a native tab, but it is based on Firefox's internal APIs, and the drag data exposed to addons don't provide the information about relationship with the native tab. Thus TST guesses a native tab was dropped if there is only one tab with the dropped URL. Otherwise TST simply treats the drop action just as dropping of a URL text or just ignores it.

[piroor]

Sorry I missed some errors with cases TST can guess dropped native tabs. More cases are now supported by recent commits.