d_printf and unprintable characters

[Martin Pool]

The browse list bug just reported is an example of a problem situation
where Samba can spit out control characters to the terminal through
d_printf.  I wonder whether it would be better for d_printf to (say)
escape 0x0c into "\x0c".  It seems like this would be safe because
it's always used to produce human-readable output, not to write to a
data file.

Which particular characters are to be considered unprintable will
depend on the character set, but I think we have enough information to
do it.

Does that sound reasonable/useful?
-- 
Martin