patch 8.1.0512: 'helplang' default is inconsistent for C and C.UTF-8 commit https://github.com/vim/vim/commit/389ab7122bec99c11ad4ce6d87cc6f38a21e4e40 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Nov 5 20:25:52 2018 +0100 patch 8.1.0512: 'helplang' default is inconsistent for C and C.UTF-8 Problem: 'helplang' default is inconsistent for C and C.UTF-8. Solution: Don't accept a value unless it starts with two letters.

/* 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);