Minimap rendering a partial preview of selection

[nilox94]

Issue Type: Bug

In few hundred lines documents, I can see how the current line is not shown on the minimap when the cursor is placed (approximately) after the second half of the document (in terms of the number of lines). When I select the whole document I can see how only the first half of the minimap is highlighted. This behavior begins when the document has more than 123 lines. e.g. in a 124 lines document, all lines except the last one are highlighted on the minimap. The rate of highlighted-lines/total-lines decreases as documents grow and tends to resemble 1/2.

VS Code version: Code - OSS 1.41.1 (26076a4, 2019-12-20T11:11:01.597Z)
OS version: Linux x64 5.4.12-1-MANJARO

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz (8 x 2552)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: disabled_software skia_renderer: disabled_off surface_control: disabled_off surface_synchronization: enabled_on video_decode: unavailable_off viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	15.38GB (4.92GB free)
Process Argv	--no-sandbox --unity-launch --no-sandbox
Screen Reader	no
VM	0%

Extensions (7)

Extension	Author (truncated)	Version
matlab-code-run	bra	1.0.2
latex-workshop	Jam	8.6.0
python	ms-	2020.1.58038
cpptools	ms-	0.26.3
Go	ms-	0.12.0
vsc-octave-debugger	pau	0.3.16
octave	toa	0.0.3

``

[RMacfarlane]

Duplicate of #89354, this should already be fixed