Markdown preview scrolling regression issue

[af4jm]

Issue Type: Bug

I have MD preview set to auto-scroll with the source file, but not for source to auto-scroll with the preview.

I recently noticed that if I add a div (e.g. line 28 in the attached file), and that div has a MD blockquote in it, the preview will always auto-scroll to the top of that div, even if you're typing hundreds of lines further down the file.

I also just noticed today that if I put a MD HR (e.g. line 15), the same thing happens, auto-scrolling stops at that point... to get auto-scrolling to behave correctly in the attached file, I need to delete the HR at line 15 and either delete line 28 or remove the blockquote from inside the div

VS Code version: Code 1.63.2 (899d46d, 2021-12-15T09:40:02.816Z)
OS version: Windows_NT x64 10.0.22000
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-8265U CPU @ 1.60GHz (8 x 1800)
GPU Status	2d_canvas: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on rasterization: enabled skia_renderer: enabled_on video_decode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	31.89GB (20.43GB free)
Process Argv	--file-uri file:///c%3A/src/AF4JM.code-workspace --crash-reporter-id 06338080-eec2-498d-98e0-cf3111dc1cde
Screen Reader	no
VM	0%

Extensions (105)

Extension	Author (truncated)	Version
html-snippets	abu	0.2.1
vscode-icalendar	af4	1.0.1
vscode-m3u	af4	1.0.0
vscode-caniuse	aga	0.5.0
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rtf	ale	2.4.0
vscode-sqlite	ale	0.14.0
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spellright	ban	3.0.60
armview	ben	0.4.5
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markdown-footnotes	bie	0.0.7
markdown-mermaid	bie	1.13.1
markdown-yaml-preamble	bie	0.1.0
vscode-tldr	bmu	1.0.0
mermaid-markdown-syntax-highlighting	bpr	1.2.2
npm-intellisense	chr	1.4.0
gitignore	cod	0.7.0
disableligatures	Coe	0.0.10
vscode-markdownlint	Dav	0.45.0
jshint	dba	0.11.0
vscode-eslint	dba	2.2.2
dendron-snippet-maker	den	0.1.6
rushcore	Dev	1.0.2
rushnav	Dev	1.0.2
githistory	don	0.6.19
xml	Dot	2.5.1
escaping-characters	drp	1.0.0
vscode-babel-coloring	dza	0.0.4
gitlens	eam	11.7.0
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scriptcsRunner	fil	0.1.0
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shell-format	fox	7.2.2
macros	ged	1.2.1
matlab	Gim	2.3.1
vscode-pull-request-github	Git	0.34.3
mdmath	goe	2.7.4
gc-excelviewer	Gra	4.0.50
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path-autocomplete	ion	1.18.0
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vscode-peacock	joh	4.0.0
gpg	jva	0.1.2
docomment	k--	0.1.30
vscode-liquid-snippets	kil	2.0.3
gnuplot	mam	1.0.5
markdown-shortcuts	mdi	0.12.0
openapi-lint	mer	1.2.0
HTMLHint	mka	0.10.0
azure-pipelines	ms-	1.195.0
vscode-azureappservice	ms-	0.23.0
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vscode-azureresourcegroups	ms-	0.4.0
vscode-azurestorage	ms-	0.12.1
vscode-azurevirtualmachines	ms-	0.4.1
vscode-bicep	ms-	0.4.1124
vscode-cosmosdb	ms-	0.18.1
csharp	ms-	1.23.17
vscode-dotnet-runtime	ms-	1.5.0
python	ms-	2021.12.1559732655
vscode-pylance	ms-	2022.1.0
jupyter	ms-	2021.11.1001550889
jupyter-keymap	ms-	1.0.0
jupyter-renderers	ms-	1.0.4
vscode-ai-remote	ms-	0.6.0
remote-containers	ms-	0.209.6
remote-ssh	ms-	0.70.0
remote-ssh-edit	ms-	0.70.0
vscode-remote-extensionpack	ms-	0.21.0
azure-account	ms-	0.9.11
azurecli	ms-	0.5.0
live-server	ms-	0.2.11
mono-debug	ms-	0.16.2
powershell	ms-	2021.12.0
vscode-node-azure-pack	ms-	0.2.1
vscode-typescript-tslint-plugin	ms-	1.3.3
azurerm-vscode-tools	msa	0.15.5
debugger-for-edge	msj	1.0.15
language-liquid	nei	0.1.1
azdo-wiki-md	ni	0.0.3
vscode-commons	red	0.0.6
vscode-yaml	red	1.2.2
kuskus-kusto-language-server	ros	1.0.20
kuskus-kusto-syntax-highlighting	ros	1.1.20
toggle-case	rya	1.0.2
vscode-hexdump	sle	1.8.1
vscode-zipexplorer	sle	0.3.1
addDocComments	ste	0.0.8
msbuild-project-tools	tin	0.4.3
shell-launcher	Tyr	0.4.1
vscodeintellicode	Vis	1.2.15
nanoid-generator	vk-	0.1.2
vscode-icons	vsc	11.8.0
JavaScriptSnippets	xab	1.8.0
markdown-all-in-one	yzh	3.4.0
t4-support	zbe	0.5.0

A/B Experiments

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vscexrecpromp3t3:30407764

[af4jm]

gist with the example MD file mentioned in my above report... https://gist.github.com/af4jm/ee2625a86e97f7e20d98119baa0def67

[mjbvz]

Does this reproduce in the latest VS Code insiders build with all extensions disabled?

[af4jm]

the div yes, the hr no... I also noticed that if the editor window is below line 250, the preview scrolls with it, but as soon as the editor scrolls back above 250, the preview jump to the div

some I other things I tried (in Insiders with no extensions & empty settings file, although all behavior both above and below is the same as non-Insider with extensions & settings):

• I removed all the table tags between lines 250-262 and the scroll behavior was still the same (so it's not an "until the next raw HTML" thing)
• I also removed the style attribute from the div on line 28, and again the behavior did not change (so it's not caused by the CSS columns)
• I added a div around the blockquote at lines 70-85, and with both divs it didn't go back to normal scroll until the MD was down to line 440
• with the div around the second blockquote (Genesis 1, lines 70-85) but not the first (Jabberwocky, lines 30-55), scroll is normal all the way down the file

seeing that last bullet point, I'm wondering if I hit an edge case rather than a regression, because this is bizarre

[vscode-triage-bot]

Hey @mjbvz, this issue might need further attention.

@af4jm, you can help us out by closing this issue if the problem no longer exists, or adding more information.

[af4jm]

I've seen this issue within the last week... definitely not fixed

[mjbvz]

I tested with that file on VS Code insiders (1.72) and don't see this issue. I tried scrolling both the editor and scrolling the preview, as well as typing in the editor

If you are still seeing problems, please specific steps to reproduce it so I can try investigate