KIO and named pipes

[Will Stephenson]

I investigated #149071 (kio_fish hangs on copying named pipe), which happens 
for the reason you would expect, and came up with a patch for kio_fish that 
detects fifos and errors.

However, I investigated a bit further and found that the handling of named 
pipes in other ioslaves is not consistent and can cause other problems.

For example: with kio_ftp, the server returns a 550 Requested action not taken 
if you try to copy a fifo.  KIO turns this into 'could not 
read /path/of/fifo'.

With kio_sftp, the sftp-server tries to read the fifo and hangs too.  

Would it be possible or desirable to detect KIO-side an attempt to read a 
fifo, and error without telling the slave to get it? 

IIUC when copying a directory, there's a listRecursive() then each file is 
get'ed individually.  This list must detect the mimetype allowing a chance to 
skip the fifo.  What about when copying a single file?

Will