Invalid HTML in diagnostics["code"] breaks hover popups.

[ShrykeWindgrace]

Describe the bug
If the code field of the diagnostic contains invalid html, the hover popup is broken

To Reproduce
Steps to reproduce the behavior:

1. Use haskell-language-server
2. hover over a line with redundant <$> hint (for example, inputForConfig config = (<> config) <$> standardIOConfig >>= inputForConfig
3. The hover popup is cut in half, and ST's console complaints about parsing errors

Expected behavior
Hover is properly formatted

Environment (please complete the following information):

• OS: Win10
• Sublime Text version: 4143
• LSP version: current master
• Language servers used: [HLS] with suggested config

Root cause
In the format_diagnostics_for_html method we append the contents of diagnostics["code"] as-is, without escaping (https://github.com/sublimelsp/LSP/blob/main/plugin/core/views.py#L1006).

As far as I understand, the specs of LSP say nothing about that field, it can be an arbitrary text. I suggest
the following diff:

diff --git a/plugin/core/views.py b/plugin/core/views.py
index cfdce3e..7af8239 100644
--- a/plugin/core/views.py
+++ b/plugin/core/views.py
@@ -1003,7 +1003,7 @@ def format_diagnostic_for_html(
         if code_description:
             code.append(make_link(code_description["href"], diagnostic.get("code")))
         else:
-            code.append(_with_color(diagnostic["code"], "color(var(--foreground) alpha(0.6))"))
+            code.append(_with_color(text2html(diagnostic["code"]), "color(var(--foreground) alpha(0.6))"))
         code.append(_with_color(")", "color(var(--foreground) alpha(0.6))"))
     else:
         code = None

I do not have a good idea on how it could impact other LSP servers, comments and suggestions are welcome.

I'll submit a PR sometime later this week.

Cheers!

[rchl]

Yes, text2html is the correct thing to use here. But there are quite a few more places that need it. Everywhere we get disagnostic code, source or the relatedInformation[0]['message]

[ShrykeWindgrace]

@rchl thanks for the confirmation! However, I am not sufficiently familiar with codebase to add that text2html in all required places, the PR will take some time=)