bug#28806: syntax highlighting in ox-odt and emacs26+ broken

[Eli Zaretskii <eliz@gnu.org>]

> From: Jay Kamat <jaygkamat@gmail.com>
> Date: Fri, 13 Oct 2017 02:29:23 -0400
> 
> 1. Compile Emacs *26* from source (emacs-26 branch)
> 2. Load an org file with the following (built-in org):
> 
> #+BEGIN_SRC c
> int main() {
>     return 0;
> }
> #+END_SRC
> 
> 3. Export to odt via C-c C-e o o 
> 4. Open file in libreoffice
> 
> Expected Results
> 
> Syntax highlighting for the code block as in emacs25
> 
> Actual Results
> 
> Code seems to be colored in a single color, interestingly, this is *not*
> black.
> 
> (I can provide screenshots if that would be helpful)
> 
> After poking around, I found a bit more information on how to reproduce
> it:
> 
> Environments with working syntax export:
> 1. Emacs25, always (unless unrelated errors are present)
> 2. Emacs26, when running org compiled with emacs 25 (from elpa/repo)
> 3. Emacs26, when running org 'interpreted' (not compiled to bytecode)
> 
> Environments with broken syntax export:
> 1. Emacs26 when compiled from source, using builtin org
> 2. Emacs26 when org is compiled with Emacs 26 (from elpa/repo)
> 
> I tested all emacs versions on org 0b83168465, changing which version
> org was compiled with by modifying the EMACS variable in local.mk in
> org. I ran everything in ~emacs -Q~.
> 
> I attempted to bisect emacs to find which change in emacs is causing
> this, bug I wasn't able to compile some older versions of emacs due to
> internal bytecode errors preventing a clean compilation. I was able to
> find that it was '14 revisions away from 5f3379b338' but I don't know if
> that's helpful.
> 
> >From what I can tell (which is probably incorrect), this seems like
> either:
> 
> 1. A bug in the new bytecode 
> 2. Some backwards-incompatible change to macros in emacs 26 that org
> didn't pick up on.
> 
> In the latter case, the change should be added to the NEWS file as a
> backwards incompatible change.
> 
> A stackexchange question about this is here:
> https://emacs.stackexchange.com/questions/36023/how-to-export-babel-source-blocks-with-syntax-highlighting-to-odt-in-org-mode-in
> 
> I posted in the org mode mailing list about this to try to get some
> initial feedback from orgmode before posting here:
> http://lists.gnu.org/archive/html/emacs-orgmode/2017-10/msg00161.html

Thanks.

Having read all of the references and discussions you've provided, I
see no evidence that this is an Emacs issue, as opposed to an Org
issue.  I think the Org developers should take a look at this first,
and only if they provide clear evidence that the problem is due to
Emacs, should the problem come here.