Undo after save on JSON files navigates to end of file

[StephenWeatherford]

Issue Type: Bug

Does not happen in stable. Still repros if all extensions are disabled.

1. Open a JSON file
2. Make any change
3. Save
4. Undo
   !) cursor navigates to the bottom of the file, gets extremely annoying

VS Code version: Code - Insiders 1.33.0-insider (f5044f0, 2019-03-28T16:20:44.233Z)
OS version: Darwin x64 18.2.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-4870HQ CPU @ 2.50GHz (8 x 2500)
GPU Status	2d_canvas: enabled checker_imaging: disabled_off flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: enabled rasterization: enabled surface_synchronization: enabled_on video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	3, 3, 3
Memory (System)	16.00GB (0.07GB free)
Process Argv
Screen Reader	no
VM	0%

Extensions (9)

Extension	Author (truncated)	Version
tslint	eg2	1.0.43
vscode-antlr4	mik	2.1.1
vscode-azurestorage	ms-	0.7.0
vscode-cosmosdb	ms-	0.10.0
azure-account	ms-	0.8.0
csharp	ms-	1.18.0
vscode-typescript-tslint-plugin	ms-	1.0.0
azurerm-vscode-tools	msa	0.5.0
vscode-docker	Pet	0.6.1

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Prompt when jumping over save points when undoing in the editor (#43716)
• Undo overwrites file after many undos (#69630)
• Undoing several newlines should undo them all together (or whichever was added at the same time) (#46152)
• Undo stack is lost on file name change (#53333)

[alexdima]

@StephenWeatherford Can you please share your settings? I cannot reproduce:

[StephenWeatherford]

Okay, so it repros only when this setting is on:

"editor.formatOnSave": true,

It also doesn't seem to repro with all editors. Try deleting one or more characters out of any string value, then save and undo.

[alexdima]

@StephenWeatherford Still no luck in reproducing. I'm using "editor.formatOnSave": true and deleting characters in a string value, then saving, then undoing:

[StephenWeatherford]

I still see this, stable and insiders, Mac and Windows. What do you need from me? It appears that there's an extra item pushed onto the undo stack that shouldn't be there.

[alexdima]

@jrieken You mentioned something today about formatting on save not picking up the editor in some cases ?

[jrieken]

@StephenWeatherford This might be #71707. Please try to reproduce with next (tomorrows) insiders build: https://code.visualstudio.com/insiders/

[jrieken]

optimistically closing as dupe

[StephenWeatherford]

Does seem to be fixed, thanks!