standards/177742: conflict of dd's bs= option with use of conv=sparse

[Matthew Rezny]

The following reply was made to PR standards/177742; it has been noted by GNATS.

From: Matthew Rezny <mrezny at hexaneinc.com>
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: standards/177742: conflict of dd's bs= option with use of
 conv=sparse
Date: Wed, 10 Apr 2013 15:31:08 +0200

 The patch I suggested got a little messed up by the web form, and it
 also contained a typo. Further, I had neglected to consider the
 C_BS flag itself should be present after masking off the few allowed
 flags, so the patch should be amended as such follows.
 
  if (ddflags & C_BS) {
      out.dbcnt = in.dbcnt;
 -    dd_out(1);
 +    dd_out((ddflags & !(C_NOERROR | C_NOTRUNC | C_SYNC)) == C_BS);
      in.dbcnt = 0;
      continue;
  }
 
 This patch has been tested to confirm conv=sparse now works as expected
 with bs= set. No other conversions have been checked with the bs=
 option and from reading the code I don't think they will.