Relative markdown-css-paths

[mattiasb]

Expected Behavior

Since #835 got merged I can now set markdown-css-paths as a file
local variable like this:

<!-- -*- markdown-css-paths: ("/home/mattiasb/Code/github.com/mattiasb/repository/stylesheet.css"); -*- -->

It would be nice to be able to let the path be relative instead like
this:

<!-- -*- markdown-css-paths: ("./stylesheet.css"); -*- -->

… and it would resolve the path to the style sheet relative to the
markdown file.

Actual Behavior

When I run markdown-preview the HTML is written to a file like
file:///tmp/burl7ynLE7.html and thus "./stylesheet.css" can't
be found.

Steps to Reproduce

With test.md:

<!-- -*- markdown-css-paths: ("./stylesheet.css"); -*- -->

# Test

Test!

… and stylesheet.css like:

h1 { color: red; }

… both in the same directory then:

1. Do M-x normal-mode to make sure the local variable is loaded.
2. Press y to allow the file local variable.
   See: Mark markdown-css-paths safe as a file local var #856.
3. In test.md do C-c C-c p
4. Notice how the header isn't red.

Software Versions

• Markdown Mode: 2.7-alpha
  • ;; Package-Version: 20241107.349
  • ;; Package-Revision: 6f59f72ca040
• Emacs: 29.4
• OS: Fedora Workstation 41