Re: bin/46743: suggested patch for second part

[Martin Husemann <martin%duskware.de@localhost>]

The following reply was made to PR bin/46743; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/46743: suggested patch for second part
Date: Sat, 7 Dec 2013 23:31:23 +0100

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 The patch below marks the "next free cluster" in the file system info
 block as uninitialized, which make fsck_msdos happy and should be
 generally ok.
 
 An alternative is to mark cluster bpb.rdcl as 0 (i.e. free) in the
 loop initializing the fats, but that code is ... "slightly" ugly:
 
             } else if (lsn >= bpb.res && lsn < dir &&
                        !((lsn - bpb.res) %
                          (bpb.spf ? bpb.spf : bpb.bspf))) {
                 mk1(img[0], bpb.mid);
                 for (x = 1; x < o.fat_type * (o.fat_type == 32 ? 3U : 2U) / 
8U; x++)
                     mk1(img[x], o.fat_type == 32 && x % 4 == 3 ? 0x0f : 0xff);
 
 Maybe just leave that loop alone and clear a few bytes afterwards conditional
 on
 
        if (o.fat_type == 32 && bpb.infs != MAXU16)
 
 However, the suggested patch is a lot simpler and I don't see any downsides.
 
 Martin
 
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 Index: mkfs_msdos.c
 ===================================================================
 RCS file: /cvsroot/src/sbin/newfs_msdos/mkfs_msdos.c,v
 retrieving revision 1.8
 diff -u -p -r1.8 mkfs_msdos.c
 --- mkfs_msdos.c       19 Oct 2013 01:09:59 -0000      1.8
 +++ mkfs_msdos.c       7 Dec 2013 22:04:08 -0000
 @@ -709,7 +709,7 @@ mkfs_msdos(const char *fname, const char
                mk4(img, 0x41615252);
                mk4(img + MINBPS - 28, 0x61417272);
                mk4(img + MINBPS - 24, 0xffffffff);
 -              mk4(img + MINBPS - 20, bpb.rdcl);
 +              mk4(img + MINBPS - 20, 0xffffffff);
                mk2(img + MINBPS - 2, DOSMAGIC);
            } else if (lsn >= bpb.res && lsn < dir &&
                       !((lsn - bpb.res) %
 
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