Exceptions from terminal

[mjbvz]

Testing #23688

• VSCode Version: 1.31-insiders
• OS Version: Ubuntu 16.04

Repo
(still trying to track down exact steps)

1. Split terminal
2. In each terminal run ls -R
3. Scroll in windows
4. Now zoom in and out a bunch and resize the windows/panes (sorry I can't track down exactly what causes this)

Bug
Every so often, I see these sort errors in the developer console after messing around:

bootstrap-window.js:202 [uncaught exception]: TypeError: Cannot read property 'get' of undefined
onUnexpectedError @ bootstrap-window.js:202
bootstrap-window.js:205 TypeError: Cannot read property 'get' of undefined
    at TextRenderLayer._forEachCell (TextRenderLayer.ts:75)
    at TextRenderLayer._drawBackground (TextRenderLayer.ts:184)
    at TextRenderLayer.onGridChanged (TextRenderLayer.ts:263)
    at Renderer.ts:198
    at Array.forEach (<anonymous>)
    at Renderer._renderRows (Renderer.ts:198)
    at RenderDebouncer._innerRefresh (RenderDebouncer.ts:49)
    at RenderDebouncer.ts:40
onUnexpectedError @ bootstrap-window.js:205
TextRenderLayer.ts:75 Uncaught TypeError: Cannot read property 'get' of undefined
    at TextRenderLayer._forEachCell (TextRenderLayer.ts:75)
    at TextRenderLayer._drawBackground (TextRenderLayer.ts:184)
    at TextRenderLayer.onGridChanged (TextRenderLayer.ts:263)
    at Renderer.ts:198
    at Array.forEach (<anonymous>)
    at Renderer._renderRows (Renderer.ts:198)
    at RenderDebouncer._innerRefresh (RenderDebouncer.ts:49)
    at RenderDebouncer.ts:40
bootstrap-window.js:202 [uncaught exception]: TypeError: Cannot read property 'replaceCells' of undefined
onUnexpectedError @ bootstrap-window.js:202
bootstrap-window.js:205 TypeError: Cannot read property 'replaceCells' of undefined
    at InputHandler._eraseInBufferLine (InputHandler.ts:718)
    at InputHandler.eraseInLine (InputHandler.ts:811)
    at Array.<anonymous> (InputHandler.ts:144)
    at EscapeSequenceParser.parse (EscapeSequenceParser.ts:507)
    at InputHandler.parse (InputHandler.ts:299)
    at Terminal._innerWrite (Terminal.ts:1372)
    at Terminal.ts:1341
onUnexpectedError @ bootstrap-window.js:205
InputHandler.ts:718 Uncaught TypeError: Cannot read property 'replaceCells' of undefined
    at InputHandler._eraseInBufferLine (InputHandler.ts:718)
    at InputHandler.eraseInLine (InputHandler.ts:811)
    at Array.<anonymous> (InputHandler.ts:144)
    at EscapeSequenceParser.parse (EscapeSequenceParser.ts:507)
    at InputHandler.parse (InputHandler.ts:299)
    at Terminal._innerWrite (Terminal.ts:1372)
    at Terminal.ts:1341

Does this issue occur when all extensions are disabled?: Yes/No

[mjbvz]

Similar to #67439 but different errors

[Tyriar]

@mjbvz I think all the exceptions have the same root cause, something in reflow corrupts the buffer and then various components try to access it at different places.