popen() and O_APPEND

[Wojtek Lerch <yyyyyy@xxxxxxx>]

If O_APPEND is set, should popen() still write where it's told to, or 
should it append to the end of the file?  According to the standard, 
popen() doesn't move the file position (presumably, either before or 
after writing), which seems to promise the former; but apparently, 
O_APPEND wins in at least two implementations (Solaris and NetBSD).  Is 
that a bug in those implementations or a defect in the standard?