PRs/Issues with Mermaid markdown causes Jasper to use the wrong webpage URL

[dinofx]

Last year GitHub added mermaid markdown support in issues, PRs, etc. Github's implementation uses an iframe to load the 3rd-party rendering code that displays the diagram.

This seems to confuse Jasper. When display a PR with URL like:

https://{enterprise hostname}/{org}/{repo}/pull/55

Jasper will instead display an address like:

https://{enterprise hostname}/viewscreen/markdown/mermaid?color_mode=light#{fragment}

Viewing this Issue in Jasper should reproduce the problem (I assume it's not specific to GH:Enterprise):

  graph TD;
      A[Example diagram]-->B[to reproduce problem];