SSH remote editing + Markdown preview + PlantUML: plantuml code section won' t show up

Type: Bug

Preliminary note: I'm note using Markdown Preview Enhanced (which has its own issues with plantuml). I'm using the native Markdown previewer.

The issue arises while previewing a Markdown file that contains a plantuml code block in an SSH remote editing session with the PlantUML extension installed. I have configured PlantUML to use a local rendering server.

Minimum markdown file that triggers the issue:

```plantuml
@startuml
Bob -> Alice: Hello
@enduml
```plantuml

Expected result: the plantuml block is rendered by the server to be displayed in the markdown preview. Observed result: a tiny default placeholder icon () is displayed in place of the diagram.

Related observations:

Preview works fine in local editing sessions using the same PlantUML rendering server as with the SSH remote edition session.
Markdown preview security settings are not at play. If I set it to strict, I get the expected error message saying some untrusted content was blocked. If I set it to any other value, I don't get any error but I get that icon in place of the diagram when using SSH remote editing.

Extension version: 0.84.0 VS Code version: Code 1.71.2 (74b1f979648cc44d385a2286793c226e611f59e7, 2022-09-14T21:03:37.738Z) OS version: Windows_NT x64 10.0.19044 Modes: Sandboxed: No Remote OS version: Linux x64 5.15.0-46-generic Remote OS version: Linux x64 5.15.0-46-generic

System Info

|Item|Value| |---|---| |CPUs|Intel(R) Core(TM) i7-9850H CPU @ 2.60GHz (12 x 2592)| |GPU Status|2d_canvas: enabled
canvas_oop_rasterization: disabled_off
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_renderer: enabled_on
video_decode: enabled
video_encode: enabled
vulkan: disabled_off
webgl: enabled
webgl2: enabled
webgpu: disabled_off| |Load (avg)|undefined| |Memory (System)|31.73GB (14.87GB free)| |Process Argv|--crash-reporter-id f254e8dd-15b4-4f7e-904b-54d84726c6e9| |Screen Reader|no| |VM|0%| |Item|Value| |---|---| |Remote|SSH: ar001vm| |OS|Linux x64 5.15.0-46-generic| |CPUs|Intel(R) Xeon(R) Silver 4314 CPU @ 2.40GHz (6 x 2394)| |Memory (System)|31.35GB (20.90GB free)| |VM|40%| |Item|Value| |---|---| |Remote|SSH: ar001vm| |OS|Linux x64 5.15.0-46-generic| |CPUs|Intel(R) Xeon(R) Silver 4314 CPU @ 2.40GHz (6 x 2394)| |Memory (System)|31.35GB (20.90GB free)| |VM|40%|

microsoft / vscode-remote-release

SSH remote editing + Markdown preview + PlantUML: plantuml code section won' t show up #7224