minor bug in dump, can cause system to hang.

[Chris Torek]

> But why fix dump when the problem is almost certainly in the disk driver?

Exactly.  Your fix is correct, but possibly incomplete.  Here is the
other change from Berkeley for the ecc code:

*** 911,916
  #endif
                bp->b_flags &= ~B_BAD;
!               mbp->mba_bcr = -(bp->b_bcount - (int)ptob(npf));
!               if (MASKREG(mbp->mba_bcr) == 0)
                        return (0);
                break;
--- 927,931 -----
  #endif
                bp->b_flags &= ~B_BAD;
!               if ((int)ptob(npf) >= bp->b_bcount)
                        return (0);
                mbp->mba_bcr = -(bp->b_bcount - (int)ptob(npf));
***************
*** 914,917
                if (MASKREG(mbp->mba_bcr) == 0)
                        return (0);
                break;
        }

--- 929,933 -----
                if ((int)ptob(npf) >= bp->b_bcount)
                        return (0);
+               mbp->mba_bcr = -(bp->b_bcount - (int)ptob(npf));
                break;
        }
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 4251)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at mimsy.umd.edu