Fix CVE-2016-4738:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-4738
https://bugs.chromium.org/p/chromium/issues/detail?id=619006

Patch copied from upstream source repository:
https://git.gnome.org/browse/libxslt/commit/?id=eb1030de31165b68487f288308f9d1810fed6880

From eb1030de31165b68487f288308f9d1810fed6880 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Fri, 10 Jun 2016 14:23:58 +0200
Subject: [PATCH] Fix heap overread in xsltFormatNumberConversion

An empty decimal-separator could cause a heap overread. This can be
exploited to leak a couple of bytes after the buffer that holds the
pattern string.

Found with afl-fuzz and ASan.
---
 libxslt/numbers.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libxslt/numbers.c b/libxslt/numbers.c
index d1549b4..e78c46b 100644
--- a/libxslt/numbers.c
+++ b/libxslt/numbers.c
@@ -1090,7 +1090,8 @@ xsltFormatNumberConversion(xsltDecimalFormatPtr self,
     }
 
     /* We have finished the integer part, now work on fraction */
-    if (xsltUTF8Charcmp(the_format, self->decimalPoint) == 0) {
+    if ( (*the_format != 0) &&
+         (xsltUTF8Charcmp(the_format, self->decimalPoint) == 0) ) {
         format_info.add_decimal = TRUE;
 	the_format += xsltUTF8Size(the_format);	/* Skip over the decimal */
     }
-- 
2.10.2

scm?id=3d363715fad0ce0fec5f22b29a97dc0fe90b3ebf'>commit</a><a href='/guix/diff/tests/modules.scm?id=3d363715fad0ce0fec5f22b29a97dc0fe90b3ebf'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/modules.scm'>
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<div class='path'>path: <a href='/guix/log/?id=3d363715fad0ce0fec5f22b29a97dc0fe90b3ebf'>root</a>/<a href='/guix/log/tests?id=3d363715fad0ce0fec5f22b29a97dc0fe90b3ebf'>tests</a>/<a href='/guix/log/tests/modules.scm?id=3d363715fad0ce0fec5f22b29a97dc0fe90b3ebf'>modules.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/modules.scm?id=3d363715fad0ce0fec5f22b29a97dc0fe90b3ebf&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-12-23 10:54:00 +0100'>2021-12-23</span></td><td><a href='/guix/commit/tests/modules.scm?id=05a9d1f378e2e13e8f759be926ea368358afc27c'>Remove VM generation dead-code.</a><span class='msg-avail'>...<span class='msg-tooltip'>This code duplicates the (gnu system image) and (gnu build image) code. Using
VM for image generation is not needed, not portable and really slow. Remove
all the VM image generation code to make sure that only the image API is used.

* gnu/build/vm.scm: Remove it. Move the qemu-command procedure to ...
* gnu/build/marionette.scm: ... here.
* gnu/local.mk (GNU_SYSTEM_MODULES): Adapt it.
* tests/modules.scm: Ditto.
* gnu/tests/install.scm: Ditto.
* gnu/system/vm.scm: Adapt it and remove expression-&gt;derivation-in-linux-vm,
qemu-img, system-qemu-image/shared-store and system-docker-image procedures.
* doc/guix.texi (G-Expressions): Adapt it.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2017-05-25 14:25:17 +0200'>2017-05-25</span></td><td><a href='/guix/commit/tests/modules.scm?id=bfe5264aa10c1af64adc5c24d0cf091562e3e09c'>modules: Raise an error when a dependency could not be found.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/modules.scm (&amp;missing-dependency-error): New error condition.
(source-module-dependencies): Raise it when 'search-path' returns #f.
* tests/modules.scm ("&amp;missing-dependency-error"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>