"Markdown" editor rendering issues

[senpos]

Issue Type: Bug

Setting up

• Install Hack font
• Turn on the font in settings
  "editor.fontFamily": "Hack, Consolas, 'Courier New', monospace",
• Set this
  "editor.renderWhitespace": "boundary",

Doing things

1. Clone this repository
2. Open README.md (not the English one!)
3. Probably it will lag already, try to scroll down and up

Short video demonstration

Error 1

  ERR Cannot read property 'type' of undefined: TypeError: Cannot read property 'type' of undefined
    at file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:669:752
    at file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:669:829
    at Object.o [as renderViewLine] (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:671:98)
    at e.renderLine (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1651:989)
    at e._finishRendering (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:478:275)
    at e.render (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:476:14)
    at e.renderLines (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:475:426)
    at t.renderText (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1699:360)
    at t._actualRender (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1770:123)
    at file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1769:366
    at z (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1761:1015)
    at t._renderNow (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1769:344)
    at t._flushAccumulatedAndRenderNow (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1766:400)
    at t._onRenderScheduled (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1769:266)
    at e.execute (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:195:972)
    at o (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:196:169)

Error 2

ERR Failed to execute 'removeChild' on 'Node': The node to be removed is not a child of this node.: Error: Failed to execute 'removeChild' on 'Node': The node to be removed is not a child of this node.
    at e._removeLinesBefore (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:477:207)
    at e.render (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:476:389)
    at e.renderLines (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:475:426)
    at t.renderText (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1699:360)
    at t._actualRender (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1770:123)
    at file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1769:366
    at z (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1761:1015)
    at t._renderNow (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1769:344)
    at t._flushAccumulatedAndRenderNow (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1766:400)
    at t._onRenderScheduled (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:1769:266)
    at e.execute (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:195:972)
    at o (file:///C:/Program Files/Microsoft VS Code Insiders/resources/app/out/vs/workbench/workbench.main.js:196:169)

A lot of these errors in Developer Tools, while i'm on the problematic area of file.

Tried both in VS Code stable and Insiders.

Will try to reproduce this issue with other fonts.
Couldn't reproduce with Iosevka and Consolas.
Well, it is not clear for me when it fails. Sometimes it works with other fonts, sometimes not. Yikes.

VS Code version: Code - Insiders 1.22.0-insider (a716373, 2018-03-14T05:15:41.910Z)
OS version: Windows_NT x64 10.0.14393

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz (4 x 3193)
Memory (System)	7.94GB (3.76GB free)
Process Argv	C:\Program Files\Microsoft VS Code Insiders\Code - Insiders.exe
Screen Reader	no
VM	0%

Extensions: none Reproduces without extensions

[senpos]

Important update

After some time playing around with this issue, I've found that this bug can be easily reproduced with next steps:

• put this into your settings "editor.renderWhitespace": "boundary",
• resize VS Code window

Here is another video example (5MB video file is here, be careful)

• 00:00 - 00:11 - without "editor.renderWhitespace": "boundary",, VS Code full screen
• 00:11 - 00:18 - with "editor.renderWhitespace": "boundary",, VS Code full screen
• 00:18 - 00:28 - with "editor.renderWhitespace": "boundary",, VS Code windowed, bug appeared (!)

[alexdima]

The root cause is 020afb7 , combined with a bug in the implementation for getLineCharCode, which would lead to the range being validated incorrectly.