My apologies - I’ve been too busy. I'll update the NEWS entry per your suggestion once we resolve the "%-<org-eval>" comment issue you flagged.

Consider this MATLAB code block and expected results.

    #+begin_src matlab :exports both :results output latex
      m = [4*pi, 3*pi; 2*pi, pi];
      result = latex(sym(m));
      disp(result)
    #+end_src
   
    #+RESULTS:
    #+begin_export latex
    \left(\begin{array}{cc} 4\,\pi  & 3\,\pi \\ 2\,\pi  & \pi  \end{array}\right)
    #+end_export

If we remove the proposed "%-<org-eval>" handling from ob-octave.el, we get the incorrect result:

    #+RESULTS:
    #+begin_export latex
    m = [4*pi, 3*pi; 2*pi, pi];
    result = latex(sym(m));
    disp(result)
    \left(\begin{array}{cc} 4\,\pi  & 3\,\pi \\ 2\,\pi  & \pi  \end{array}\right)
    #+end_export

In this case, the *MATLAB* buffer contains:

    >> m = [4*pi, 3*pi; 2*pi, pi];
    result = latex(sym(m));
    disp(result)
    'org_babel_eoe'
    m = [4*pi, 3*pi; 2*pi, pi];
    >> result = latex(sym(m));
    >> disp(result)
    \left(\begin{array}{cc} 4\,\pi  & 3\,\pi \\ 2\,\pi  & \pi  \end{array}\right)
    >> 'org_babel_eoe'
   
    ans =
   
        'org_babel_eoe'
   
    >>

I suspect that the issue is that the MATLAB echo's all commands and that there's noting wrong with comint. For example, matlab-shell buffer, *MATLAB*, the current buffer and at the MATLAB promot, ">>",

    M-: RET (comint-send-string (get-buffer-process (current-buffer)) "pwd\n") RET

Results in:

    #+begin_example
    >> pwd
   
    ans =
   
        '/home/ciolfi/tmp'
    #+end_example

Therefore, the adding "%-<org-eval>" MATLAB comments to the code being evaluated, then stripping the echo'd lines containing the "%-<org-eval>" is probably the best option.

Thanks

Another thought is we could update org-babel-comint-with-output to have an option like:

     (BUFFER EOE-INDICATOR REMOVE-ECHO FULL-BODY EOL-FILTER-INDICATOR)

where optional EOL-FILTER-INDICATOR is text, typically a comment, that is appended to each line in FULL-BODY before it is evaluated. After evaluation, each line in the result containing EOL-FILTER-INDICATOR is removed from the result.

This way, if another language encounters this issue, they can leverage this service.

Thanks