Syntax highlighting for YAML literal scalars shows errors for otherwise invalid strings

[heaths]

Issue Type: Bug

When editing YAML - such as .vsts-ci.yml files, it's not uncommon to use a literal scalar like so:

testAssemblyVer2: |
  **\$(BuildConfiguration)\*mocks*.dll
  **\$(BuildConfiguration)\*test*.dll
  **\$(BuildConfiguration)\Win32\*test*.dll
  !**\obj\**

According to http://yaml.org/spec/1.2/spec.html#id2795688, any string therein should be literal and cannot be escaped; however, VSCode shows all strings having errors or otherwise incorrect. These cannot be quoted, or the quotes will - as spec'd - end up in the VSTS tasks (see screenshot).

VS Code version: Code 1.25.1 (1dfc5e5, 2018-07-11T15:43:53.668Z)
OS version: Windows_NT x64 10.0.17134

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz (8 x 3408)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software rasterization: disabled_software video_decode: enabled video_encode: enabled vpx_decode: enabled webgl: enabled webgl2: enabled
Memory (System)	31.92GB (24.08GB free)
Process Argv	C:\Program Files\Microsoft VS Code\Code.exe .
Screen Reader	no
VM	0%

Extensions (15)

Extension	Author (truncated)	Version
vscode-sidebar	Acr	1.0.0
xml	Dot	2.3.1
vscode-guid	hea	1.3.1
vscode-azurefunctions	ms-	0.9.1
vscode-azurestorage	ms-	0.4.0
vscode-cosmosdb	ms-	0.8.0
python	ms-	2018.6.0
azure-account	ms-	0.4.1
cpptools	ms-	0.17.6
csharp	ms-	1.15.2
Go	ms-	0.6.84
PowerShell	ms-	1.8.1
team	ms-	1.136.0
debugger-for-chrome	msj	4.8.0
vscode-docker	Pet	0.0.27

[heaths]

Folded blocks have a similar problem:

packagesToPush: >
  $(Build.SourcesDirectory)\**\*.nupkg;
  !**\*.symbols.nupkg;
  !**\packages\**\*.nupkg;

...yields:

[aeschli]

marking as dup textmate/yaml.tmbundle#26

[heaths]

@aeschli, how do you track insertion of syntax changes, or are any available in textmate's repos automatically transformed and inserted during VSCode build?

[aeschli]

It's done manually. I update all grammars at least once every release. We have a script that reads the grammars from the original. The copy has additional properties to document what original commit the copy is from.
Just ping me anytime if you want me to update a particular grammar.