From 9fans@cse.psu.edu Wed Nov 29 21:44:59 EST 1995
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From: forsyth@plan9.CS.york.ac.UK
Subject: Re: VGA Hell * 2 (Stealth 64 & Phantom 64)
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Date: Thu, 23 Nov 1995 22:48:04 GMT
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>>tar file ok, however fs/tarfs gives a checksum error on the first
>>file.

try this:

vortex% diff /n/cd/sys/src/cmd/tapefs/tarfs.c .
132c132
< 		i += *cp;
---
> 		i += *cp & 0xFF;



From cse.psu.edu!9fans-outgoing-owner Sun Apr  7 01:00:23 1996
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From:	scott@angora.cse.psu.edu
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tarfs reports checksum errors on some tarfiles (generated by gnutar, I think),
because it computes the checksum over all TBLOCK chars, but only reads the
header before doing so.  The following patch seems to fix the problem.

term% diff /n/cd/sys/src/cmd/tapefs/tarfs.c .
38c38
< 	long blkno, isabs, chksum, linkflg;
---
> 	long blkno, isabs, chksum, linkflg, t;
47c47
< 		if (read(tapefile, (char *)&dblock.dbuf, sizeof(dblock.dbuf))<sizeof(dblock.dbuf))
---
> 		if (read(tapefile, (char *)&dblock, sizeof(dblock))<sizeof(dblock))
60,61c60,61
< 		if (chksum != checksum()){
< 			fprint(1, "bad checksum on %.28s\n", dblock.dbuf.name);
---
> 		if (chksum != (t=checksum())){
> 			fprint(1, "bad checksum %o != %o on %.28s\n", chksum, t, dblock.dbuf.name);
132c132
< 		i += *cp;
---
> 		i += *cp & 0xff;