Cutting in Python Notebook (.ipynb) double cuts

Issue Type: Bug

Opening this per @rchiodo request. This issue is related to microsoft/vscode-python#11796.

Watch me cut (Ctrl+X) and paste (Ctrl+V) two lines of text in a blank notebook. The first time everything works as expected, however, cutting for the 2nd time causes the line of text below (foo bar barf) to disappear.

This bug was first introduced in vscode-insiders version 1.47.0-1593495868. The version just before that (1.47.0-1593413883) works as expected:

Extension version: 2020.7.93060-dev VS Code version: Code - Insiders 1.47.0-insider (da73d2d11540232a5c75788ac0c9b41c3d432b2d, 2020-06-30T05:36:03.333Z) OS version: Linux x64 5.4.0-39-generic

System Info

Item	Value
CPUs	Intel® Core™ i7-1065G7 CPU @ 1.30GHz (8 x 1446)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: disabled_software skia_renderer: disabled_off_ok video_decode: unavailable_off viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	15.23GB (3.35GB free)
Process Argv	–no-sandbox --unity-launch
Screen Reader	no
VM	0%
DESKTOP_SESSION	ubuntu
XDG_CURRENT_DESKTOP	Unity
XDG_SESSION_DESKTOP	ubuntu
XDG_SESSION_TYPE	x11

[rchiodo]

I repro’d with the coding cat webview sample. Going to log an issue on VS code. https://github.com/microsoft/vscode/issues/101946

[rchiodo]

Seems others have verified on Mac. Upgrade to VS code 1.48.insiders if you want the fix.