Re: Bug: Org mode fails to compile using Emacs 24.5-r10 [9.4.5 (9.4.5-g3ea248 @ /home/yantar92/.emacs.d/straight/build/org/)]

[Kyle Meyer]

Ihor Radchenko writes:

> I was recently testing Org mode using old Emacs versions. Running make
> on master fails with the following errors and warnings:

Here are a few notes on ones present in maint that I've glanced at.

> Compiling /home/yantar92/Git/org-mode/lisp/ol-eww.el...
>
> In org-eww-store-link:
> ol-eww.el:76:36:Warning: reference to free variable `eww-data'
>
> In end of data:
> ol-eww.el:182:1:Warning: the function `eww-current-url' is not known to be
>     defined.

These are guarded by version checks.  Ideally the compatibility kludges
would be done in a way to avoid the warnings (e.g., with boundp/fboundp
guards) or at least wrapped in with-no-warnings, though harmless
warnings on Emacs 24 don't really matter too much at this point.

> In end of data:
> org-agenda.el:10851:1:Warning: the following functions are not known to be
>     defined: funcall-interactively, window-font-width

Adding a compatibility function for window-font-width is tricky.  We
can't just add something like below to org-compat because font-info (C
code) wasn't added until Emacs 25.

  (if (fboundp 'window-font-width)
      (defalias 'org-window-font-width 'window-font-width)
    (defun org-window-font-width (&optional window face)
      (with-selected-window (window-normalize-window window t)
        (if (display-multi-font-p)
            (let* ((face (if face face 'default))
                   (info (font-info (face-font face)))
                   (width (aref info 11)))
              (if (> width 0)
                  width
                (aref info 10)))
          (frame-char-width)))))

> In org-display-inline-images:
> org.el:16554:57:Warning: reference to free variable `image-map'

This warning is now gone (df84100d0), though functionally it was fine
due to a version check.

> In end of data:
> org.el:21292:1:Warning: the function `make-process' is not known to be
>     defined.

This should be addressed by 869b7a21b.