The main change is to allow input from user-specified methods,
when they are specified with CURLOPT_READFUNCTION.
All calls to fflush(stdout) in telnet.c were removed, which makes
using 'curl telnet://foo.com' painful since prompts and other data
are not always returned to the user promptly. Use
'curl --no-buffer telnet://foo.com' instead. In general,
the user should have their CURLOPT_WRITEFUNCTION do a fflush
for interactive use.
Also fix assumption that reading from stdin never returns < 0.
Old code could crash in that case.
Call progress functions in telnet main loop.
Signed-off-by: Ben Greear <greearb@candelatech.com>
38d2afcefb