vim-patch:8.2.4840: heredoc expression evaluated even when skipping

Problem:    Heredoc expression evaluated even when skipping.
Solution:   Don't evaluate when "skip" is set. (closes vim/vim#10306)

05c7f5d3d0

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/eval/vars.c

@@ -227,7 +227,7 @@ static list_T *heredoc_get(exarg_T *eap, char *cmd)
     }
 
     char *str = theline + ti;
-    if (evalstr) {
+    if (evalstr && !eap->skip) {
       str = eval_all_expr_in_str(str);
       if (str == NULL) {
         // expression evaluation failed