Re: Invalid link generation for equations

[Jonathan Corbet <corbet@lwn.net>]

[Adding Konstantin and Mauro, in case anybody has any thoughts...]

Kevin Brodsky <kevin.brodsky@arm.com> writes:

> Hi,
>
> I have noticed that links to equation images are not generated correctly
> on docs.kernel.org. For instance, Documentation/mm/memory-model.rst has:
>
>     .. math::
>     
>        NR\_MEM\_SECTIONS = 2 ^ {(MAX\_PHYSMEM\_BITS - SECTION\_SIZE\_BITS)}
>
> The generated HTML [1] shows the source code instead of the rendered
> equation because the link to the image [2] is broken. [3] does however
> exist. The issue seems to be that the link is relative to the root, even
> though we are in a subfolder (mm/ here).
>
> Given my non-existent knowledge of Sphinx I have no idea what the fix
> might be, but I thought I'd report this at least :)
>
> - Kevin
>
> [1] https://docs.kernel.org/mm/memory-model.html#sparsemem
> [2]
> https://docs.kernel.org/mm/_images/math/d99368220bfdedf1a888b1c09eb7236a8c87d079.png
> [3]
> https://docs.kernel.org/_images/math/d99368220bfdedf1a888b1c09eb7236a8c87d079.png

OK, so this is more than passing strange...I can't reproduce that
problem locally.  The HTML I get is:

  <img src="../_images/math/d9936822[...]

On docs.kernel.org, instead:

  <img src="_images/math/d9936822[...]

Note the missing "../".

I will confess that I don't have a great understanding of how imgmath
works and how that link gets set.  We could "fix" the problem generally
by setting imgmath_embed=True, but it would be good to understand what's
actually happening here.

Thanks,

jon