Hi Timothy,

Thanks for your work. I hope this can be merged.

Here are a few comments.

Doesn't this line in ~org-toggle-inline-results-display~ throw the
configured delimiters away when called twice ?
: (setq org-inline-src-prettify-results (not org-inline-src-prettify-results))

I think the =org-block= face should only be applied to the actual
code, note the =src_lang= part, nor the result. For normal src blocks,
it is only used inside the block.

The ~org-src-font-lock-fontify-block~ function could be modified to
take an optional =inline= argument. When =t=, it should not set the
=multiline= font property. Although this is very minor, it would allow
one to easily advice this function to behave differently in inline src
blocks. For example, to not use the =org-block= face in this case.

I think the default parenthesis pair around results are bad. I much
preferred your original brackets. Yes, as Tom said, they look alien,
but alien is appropriate for use of ~prettify-symbols~.

Since ~prettify-symbols~ seems to be raising some usability concerns,
perhaps ~org-inline-src-prettify-results~ should default to ~nil~.
It'd be unlike org to hide things from the user in the default
configuration.

As Tom points out, the two faces used (for the =src_= and bracket and
the language part) should be customizable. The default value you chose
are fine IMO. Perhaps the language one could also be used to highlight
the language of normal src blocks, though It might be easier to use a
single face.

Timothy writes:
P.S. Nitpick: You do not need to run fontification in while loops. Just
fontifying next match before limit should be enough. Font-lock will call
the function again if needed.
I'm guessing for this to work I'd need to return the final char
fortified? Or is the moving of point enough?

Maybe related - I've noticed this doesn't seem to work with multiple
src_ blocks per line, might you have any insight here?

You need only return =t= if some fontification has been done (and set
point after the fontified part). If your function returns =t=, it will
be called again.

A case can be made for keeping the loop though. It works fine and is
clearer since the aforementioned fontlock behaviour is poorly
documented. Really, the only downside is the loss of consistency, since
the function ~org-fontify-meta-lines-and-blocks-1~ doesn't loop.

Regards,

-- 
Sébastien Miquel