Description of the Issue

After multi-line tab reduces to single line tab by closing tabs, click on an inactive tab and dragging it slightly will change the tab (name and content) to another one.

Steps to Reproduce the Issue

1. Set tab mode in multi-lines mode
2. open a lot of files to have multi-lines tab
3. close tab one by one until it becomes single line tab
4. click an inactive tab named foo by dragging it very slightly

Expected Behavior

foo is activated

Actual Behavior

bar is activated

Debug Information

Notepad++ v7.8.1 (32-bit)
Build time : Oct 27 2019 - 22:46:07
Path : C:\Program Files (x86)\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS Name : Windows 10 Enterprise (64-bit)
OS Version : 1903
OS Build : 18362.418
Plugins : mimeTools.dll NppConverter.dll NppExport.dll