STR

1. launch x64 Notepad++, create a new empty tab ("new xxx") or open a file smaller than the 2047MB
2. paste/enter there any data which in sum with the already existing ones in the Notepad++ filebuffer exceeds 2048MB
3. scroll (click) in the document beyond position 2147483647 (2GB)
4. Notepad++ either crashes or displays nonsense NUL-chars instead of the entered data
   

Debug Information

Any x64 N++ v8.3-v8.6.5.
More info in the #14944