STR:
Give keyboard focus to a "not-editor" element (e.g. the Incremental Search Bar).
Left-click the current document's tab.

Result:
The editor does not get the focus.

Expected Result:
The expected behavior is that the editor should get the focus.
Also, practically it can be useful in many cases (e.g. if you want to move focus to the editor without changing the caret position or if you want to keep a selection).

Notepad++ v7.8.3 (32-bit)
Build time : Jan 17 2020 - 18:20:02
Path : C:---\notepad++.exe
Admin mode : ON
Local Conf mode : ON
OS Name : Windows 7 Enterprise (32-bit)
OS Build : 7601.23964
Plugins : ComparePlus.dll HTMLTag_unicode.dll MenuIcons.dll PythonScript.dll _CustomizeToolbar.dll