This function is making asynchronous commands fail because it tries to
add string literal to spacemacs-useful-buffers-regexp while add-to-list
only works when first argument is a symbol and the second is an
element. Otherwise, it throws this error and stop all async commands to
do any further work at this point:
if: Wrong type argument: symbolp
This commit fixes the following issues:
- Don't add spacemacs//mark-repl-as-useful to
buffer-list-update-hook. We only need this function to switch to next
or previous buffer. So, better check when and only when those commands
are actually used.
- As a result, we remove the function since it's unneeded anymore.
- Do the checking in of comint-mode in spacemacs-useful-buffer-p
function. Better do it in one place than scatter the logic in a hook
and this function.
- Change useless-buffer-p to accept an actual buffer object and check
for buffer name inside.
