+ * before setting up the terminal modes, etc., and cannot use the timeout or
+ * buffering functions.
+ *
+ * We check if the terminal description has the ECMA-48 CPR (cursor position
+ * report) in u7 and the response in u6. The two variations of is_expected()
+ * cover the termcap style and terminfo style, and are equivalent as far as we
+ * are concerned. For analyzing the response, we wait (a short time) for 'R'
+ * to be echoed, and then check if we received two integers in the response.
+ *
+ * In principle, this could run on "any" ECMA-48 terminal, but in practice,
+ * there is a scenario using GNU screen where it uses ncurses with a partially
+ * configured pseudo-terminal, and the CPR response goes to the wrong place.
+ * So we do a simple check to exclude pseudo-terminals.