Do not overwrite clipboard contents on C-Backspace

[phoe]

Expected behavior

I want C-Backspace to not overwrite the most recent thing I have pasted in the clipboard.

Actual behavior

Hitting C-Backspace puts the deleted characters into the kill ring, overwriting whatever I had in the clipboard.

Steps to reproduce the problem

Hit C-Backspace and then try to paste.

Environment & version information

• smartparens version: 20200324.2147
• Active major-mode: slime-repl-mode
• Smartparens strict mode: nil
• Emacs version (M-x emacs-version): GNU Emacs 26.3 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.20) of 2020-05-17, modified by Debian
• Starterkit/Distribution: Spacemacs
• OS: gnu/linux

[phoe]

Fixed by remapping C-Backspace to sp-backward-delete-word.

[phoe]

Actually not fixed. Issuing (define-key smartparens-mode-map (kbd "<C-backspace>") 'sp-backward-delete-word) in IELM and hitting C-backspace several times causes erratic behavior, as the kill ring is seemingly cycled over.

[Fuco1]

Fixed in #1169