patch 8.2.4166: undo synced when switching buffer in another window Commit: https://github.com/vim/vim/commit/e615db06046312e74886fa1ef98feb5a9db2a7c3 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Jan 20 21:00:54 2022 +0000 patch 8.2.4166: undo synced when switching buffer in another window Problem: Undo synced when switching buffer in another window. Solution: Do not sync undo when not needed. (closes https://github.com/vim/vim/issues/9575)

/* auto/if_perl.c */
int perl_enabled(int verbose);
void perl_end(void);
void msg_split(char_u *s, int attr);
void perl_win_free(win_T *wp);
void perl_buf_free(buf_T *bp);
void ex_perl(exarg_T *eap);
void do_perleval(char_u *str, typval_T *rettv);
void ex_perldo(exarg_T *eap);