Fix a bug whereby 'mformat' could end up passing uninitialized bytes
to write(2).  This could be reproduced with:

  mformat -C -f 1440 -L 16  -N 77777777 -i  /tmp/x ::

where the output of /tmp/x would be non-deterministic.

Patch by Ludovic Courtès <ludo@gnu.org>.

--- mtools-4.0.23/mformat.c	2019-04-21 00:12:01.496116195 +0200
+++ mtools-4.0.23/mformat.c	2019-04-21 00:12:36.675967157 +0200
@@ -927,6 +927,7 @@ void mformat(int argc, char **argv, int
 	
 	char *endptr;
 
+	memset(&boot.bytes, '\0', sizeof boot);
 	hs = hs_set = 0;
 	argtracks = 0;
 	argheads = 0;

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<tr><td><span title='2023-06-14 14:52:21 +0300'>2023-06-14</span></td><td><a href='/guix/commit/gnu/bootloader/u-boot.scm?id=39250fc6229d60b7ae397749caf1e4c99e49b419'>gnu: bootloader: Add u-boot-sifive-unmatched-bootloader.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/bootloader/u-boot.scm (install-sifive-unmatched-u-boot,
u-boot-sifive-unmatched-bootloader): New variables.
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2023-01-18 21:25:25 -0500'>2023-01-18</span></td><td><a href='/guix/commit/gnu/bootloader/u-boot.scm?id=9530ee9f9c89cbbf35589727e9fdb373ed7f47fa'>gnu: Add u-boot-ts7970-q-2g-1000mhz-c-bootloader.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/bootloader/u-boot.scm (u-boot-ts7970-q-2g-1000mhz-c-bootloader): New
variable.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-12-28 22:14:16 -0500'>2022-12-28</span></td><td><a href='/guix/commit/gnu/bootloader/u-boot.scm?id=d6ea9f8b38df7de1194d8106488a8c33cce64fd1'>gnu: u-boot-am335x-boneblack: Revert to old name.</a><span class='msg-avail'>...<span class='msg-tooltip'>This reverts to the name this package had previous to commit
c2c1dfdf5760873f1db86d14873f725a105f7feb ("gnu: bootloader: Add U-Boot
packages for Raspberry Pi models."), which caused the package name to be
derived from the board name.

* gnu/packages/bootloaders.scm (u-boot-am335x-evm-boneblack): Remove the
NAME-SUFFIX keyword argument.  Specify the full name via the name field.
* gnu/bootloader/u-boot.scm (u-boot-beaglebone-black-bootloader): Adjust to
the renamed package.

Reported-by: Vagrant Cascadian &lt;vagrant@debian.org&gt;
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-12-20 21:29:25 -0500'>2022-12-20</span></td><td><a href='/guix/commit/gnu/bootloader/u-boot.scm?id=c04528d2a2597d79278833f3607c806278253446'>gnu: u-boot-am335x-evm-boneblack: Fix variable name.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/bootloaders.scm (u-boot-am335x-boneblack): Rename to...
(u-boot-am335x-evm-boneblack), to match the package name.
* gnu/bootloader/u-boot.scm (u-boot-beaglebone-black-bootloader): Adjust
accordingly.
</span></span></td><td>Maxim Cournoyer</td></tr>