Cheat sheet is empty (Emacs-28.0.50)

[naoking158]

I started using this wonderful package.

When I tried to open the cheat sheet, nothing showed up.

I have no idea what to do due to no errors or warnings. I would appreciate your help.

Thanks.

Expected behavior

A cheat sheet will appear.

Actual behavior

No appear.

Steps to reproduce the problem

M-x sp-cheat-sheet

Backtraces if necessary (M-x toggle-debug-on-error)

No error message.

Environment & version information

• smartparens version: 20210529.1129
• Active major-mode: lisp-interaction-mode
• Emacs version (M-x emacs-version): GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin20.6.0, NS appkit-2022.60 Version 11.5.1 (Build 20G80)) of 2021-08-08
• Spacemacs/Evil/Other starterkit (specify which)/Vanilla: Vanilla
• OS: darwin

[conao3]

Please try on Emacs-27.2 instead of HEAD Emacs. Emacs 28.0 is develop channel and unstable Emacs. And please invoke Emacs with emacs -q.

[naoking158]

@conao3 , thank you for your advice.

I checked with Emacs-27.2 and 28.0 with the minimum configuration. In v27.2, the cheat sheet was displayed correctly, so it seems that something is in conflict with v28.0.

[Fuco1]

Well, this function kind of depends on the internals of help mode so if that changed it will break. When v28 comes out we'll have to fix it.

[sonofjon]

Emacs 28 is now released. I still see this probelm on Emacs 28.2.50.

[radenling]

This problem is due to a change in locate-file-internal (used by locate-file which is used by locate-library) which swaps the found file with the natively compiled file if found. This means it returns a file with a eln suffix. locate-file in turn has a special case for this where it looks up which source file the eln file was compiled from and returns that. So in this case it would return something like '/smartparens.el'. This is the value that sp-cheat-sheet uses to find the loaded functions in load-history but load-history records the functions as loaded from the elc file (so the compiled bytecode file) which means that coammands in sp-cheat-sheet will be empty.

I found the way this works a little confusing and it seems to have been cleaned up on the emacs-29 branch. But waiting for that is probably not an option so my suggestion for fixing this is replacing the loop extracting the commands from load-history with something that doesn't rely on file extensions. Using feature-symbols from loadhist.el is one solution which would look like this:

 (cl-loop for i in (cdr (feature-symbols 'smartparens))
          if (and (consp i) (eq (car i) 'defun) (commandp (cdr i)))
          collect (cdr i)))

I can open a pull request if this seems like the right way to go?

[Fuco1]

Yes, seems to be a good approach @radenling.

For (and (consp i) (car i)) you can use car-safe which is a built-in C function doing just that.

/* Take the car or cdr of something whose type is not known.  */
INLINE Lisp_Object
CAR_SAFE (Lisp_Object c)
{
  return CONSP (c) ? XCAR (c) : Qnil;
}

Don't forget to add require for loadhist somewhere to load the feature-symbols.