Fix CVE-2018-1000097:

https://security-tracker.debian.org/tracker/CVE-2018-1000097
https://nvd.nist.gov/vuln/detail/CVE-2018-1000097

Patch taken from upstream bug report:
https://lists.gnu.org/archive/html/bug-gnu-utils/2018-02/msg00005.html

diff --git a/src/unshar.c b/src/unshar.c
index 80bc3a9..0fc3773 100644
--- a/src/unshar.c
+++ b/src/unshar.c
@@ -240,7 +240,7 @@ find_archive (char const * name, FILE * file, off_t start)
       off_t position = ftello (file);
 
       /* Read next line, fail if no more and no previous process.  */
-      if (!fgets (rw_buffer, BUFSIZ, file))
+      if (!fgets (rw_buffer, rw_base_size, file))
 	{
 	  if (!start)
 	    error (0, 0, _("Found no shell commands in %s"), name);
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<tr><td><span title='2022-11-19 13:42:30 +0000'>2022-11-19</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=bad8d9630b0431f34d9ad6f800d3a799a9fde413'>gnu: irssi: Update to 1.4.3.</a><span class='msg-avail'>...</span></td><td>jgart</td></tr>
<tr><td><span title='2022-11-05 10:13:54 -0300'>2022-11-05</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=0b38a34c5786b0f69cb44dc439c2a53df2815975'>gnu: srain: Update to 1.5.0.</a><span class='msg-avail'>...</span></td><td>Vinicius Monego</td></tr>
<tr><td><span title='2022-08-21 15:55:46 -0300'>2022-08-21</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=78ff8159816b038b959c8c5912f0173eb506fcab'>gnu: srain: Update to 1.4.1.</a><span class='msg-avail'>...</span></td><td>Vinicius Monego</td></tr>
<tr><td><span title='2022-07-31 21:55:48 -0400'>2022-07-31</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=eef8e2ec46c4155980815e00a394428c0c3de075'>gnu: qttools: Rename to qttools-5.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-07-31 21:55:44 -0400'>2022-07-31</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=5f228543394244f479b6a460326fa5f1a4a40998'>gnu: qtmultimedia: Rename to qtmultimedia-5.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-07-31 21:55:43 -0400'>2022-07-31</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=1ef04fb2288dade3ad2883026ae286a68ef13a1e'>gnu: qtsvg: Rename variable to qtsvg-5.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-07-18 14:17:52 +0300'>2022-07-18</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=f44dff89ad31a275630f0cb10a4addaea20d71d8'>gnu: weechat: Update to 3.6.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2022-06-18 13:07:09 -0300'>2022-06-18</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=321f445bd12f61d1b2a4cbd7b8b3d78e13125192'>gnu: srain: Update to 1.4.0.</a><span class='msg-avail'>...</span></td><td>Vinicius Monego</td></tr>
<tr><td><span title='2022-06-05 02:00:00 +0200'>2022-06-05</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=898511205cb8e2f3e6f522c779b0cd9fc42fdfbf'>gnu: irssi: Edit description.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2022-06-05 02:00:08 +0200'>2022-06-05</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=c23d4871a609018b16ce27f2a131f9a20bf075c2'>gnu: irssi: Update to 1.4.1.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2022-03-30 20:52:14 +0300'>2022-03-30</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=ecb2603046dfc745a84314ba5921e082a3a68e22'>gnu: weechat: Update to 3.5.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2022-03-20 16:21:54 +0200'>2022-03-20</span></td><td><a href='/guix/commit/gnu/packages/irc.scm?id=f243e6d8755e6e0dc11f6260828e8d1b89c86078'>gnu: weechat: Update to 3.4.1.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>