#1520 lines() and chars() return incorrect result after partial read to stdin.

[Rick McGuire]

Tested on latest 5.0.0 build. With this small program,

say "Enter data"
call syssleep 15
say "Lines() is" lines() "Chars() is" chars()

say charin()
say "Lines() is" lines() "Chars() is" chars()
say linein()
say "Lines() is" lines() "Chars() is" chars()

After the first charin() call, both lines() and chars() are reporting 0, but the remainder of the entered line is still available as shown by the subsequent linein() call.

[Rick McGuire]

This patch is working on Windows, but I'm unable to test the *ix version. It probably also needs a full run of the i/o refression tests.

[Erich]

Tested on Linux, ran full regression tests on Windows and Linux.
Fixed code with revision [r11347]