[Bug-tar] Documentation for warning (3.9) not accurate

[Tobias Mark]

Chapter 3.9 (http://www.gnu.org/software/tar/manual/tar.html#SEC48) say:
"Warning messages are output to the standard error and they do not affect the exit 
code of|tar|  command."

However the warning"%s: file changed as we read it"  in fact only appears with 
a changed (non-zero) exit code.
According to multiple discussions (for example: 
http://lists.gnu.org/archive/html/bug-tar/2007-08/msg00042.html)
this is the intended behaviour, so the documentation should be fixed?

I would like it even better if--warning=no-file-changed could be used to 
disable this non-zero exit code.