Fix regression caused by fix for CVE-2016-0718 when building with -DXML_UNICODE.

Discussion:

https://sourceforge.net/p/expat/bugs/539/

Patch copied from upstream source repository:

https://sourceforge.net/p/expat/code_git/ci/af507cef2c93cb8d40062a0abe43a4f4e9158fb2/

From af507cef2c93cb8d40062a0abe43a4f4e9158fb2 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Sun, 17 Jul 2016 20:22:29 +0200
Subject: [PATCH 1/2] Fix regression bug #539 (needs -DXML_UNICODE)

Thanks to Andy Wang and Karl Waclawek!
---
 expat/lib/xmlparse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
index b308e67..0d5dd7b 100644
--- a/lib/xmlparse.c
+++ b/lib/xmlparse.c
@@ -2468,7 +2468,7 @@ doContent(XML_Parser parser,
                        &fromPtr, rawNameEnd,
                        (ICHAR **)&toPtr, (ICHAR *)tag->bufEnd - 1);
             convLen = (int)(toPtr - (XML_Char *)tag->buf);
-            if ((convert_res == XML_CONVERT_COMPLETED) || (convert_res == XML_CONVERT_INPUT_INCOMPLETE)) {
+            if ((fromPtr >= rawNameEnd) || (convert_res == XML_CONVERT_INPUT_INCOMPLETE)) {
               tag->name.strLen = convLen;
               break;
             }
-- 
2.10.0
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<tr><td><span title='2021-07-07 23:54:20 -0400'>2021-07-07</span></td><td><a href='/guix/commit/etc/init.d?id=4cbe0127a668cbcc64087c5d311308b59d39b104'>guix-install.sh: Prompt for configuring substitutes discovery.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2020-03-11 02:45:33 +0100'>2020-03-11</span></td><td><a href='/guix/commit/etc/init.d?id=73fbe04107d38f4561636c74d28d7a4935cbb1ef'>Add system start-up files for guix-daemon.</a><span class='msg-avail'>...</span></td><td>Danny Milosavljevic</td></tr>