sp-backward-kill-word mis-balances tree structure

[kanubacode]

Expected behavior

sp-backward-kill-word should not delete closing parentheses, leaving the expression's tree structure damaged.

Actual behavior

sp-backward-kill-word when preceded by certain input, deletes closing parentheses delimiters in addition to the word.

Steps to reproduce the problem

For a simple reproducible test, I had a function in Common Lisp called @ that I wanted to mark as inlined, so I added:

(declaim (inline @))_

Where _ denotes the current point. Invoking sp-backward-kill-word to remove the @ character will leave you with this:

(declaim (inline _

As far as I can tell, this seems to only occur when the word contains the @ character.

Environment & version information

• smartparens version: b8bdd9265e6950e038bbcd68ead5582c6964baf2
• Active major-mode: lisp-mode
• Smartparens strict mode: t
• Emacs version (M-x emacs-version): GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.22, cairo version 1.17.3) of 2020-08-28
• Starterkit/Distribution: Evil
• OS: gnu/linux

[Fuco1]

I can reproduce this. Will have a look.