Patch derived from discussion at https://savannah.nongnu.org/bugs/?37503

--- texi2html-5.0/texi2html.pl	2010-06-30 17:01:27.000000000 -0500
+++ texi2html-5.0/texi2html.pl	2014-07-09 01:17:57.062990582 -0500
@@ -2589,7 +2589,12 @@
     my $state = shift;
 
     # FIXME this should be done only once, for @documentencoding
-    my $encoding = lc(Texi2HTML::Config::get_conf('DOCUMENT_ENCODING'));
+    my $encoding;
+    my $input_encoding = Texi2HTML::Config::get_conf('documentencoding');
+    if (defined($input_encoding))
+    {
+      $encoding = lc($input_encoding);
+    }
     if (defined($encoding) and $encoding ne '' and exists($Texi2HTML::Config::t2h_encoding_aliases{$encoding}))
     {
        $encoding = $Texi2HTML::Config::t2h_encoding_aliases{$encoding};

Fix failures in test/encodings.

--- texi2html-5.0/texi2html.pl	2014-07-09 01:22:06.000000000 -0500
+++ texi2html-5.0/texi2html.pl	2014-07-10 23:23:47.182097602 -0500
@@ -53,6 +53,7 @@
 # for translations
 #use encoding 'utf8';
 #use utf8;
+binmode STDERR, ':encoding(utf8)';
 
 #
 # According to
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<div class='path'>path: <a href='/guix/log/?id=9b049de84ed101e2c0a5d071e76f424b3bc46bd9'>root</a>/<a href='/guix/log/gnu?id=9b049de84ed101e2c0a5d071e76f424b3bc46bd9'>gnu</a>/<a href='/guix/log/gnu/packages?id=9b049de84ed101e2c0a5d071e76f424b3bc46bd9'>packages</a>/<a href='/guix/log/gnu/packages/libbsd.scm?id=9b049de84ed101e2c0a5d071e76f424b3bc46bd9'>libbsd.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/gnu/packages/libbsd.scm?id=9b049de84ed101e2c0a5d071e76f424b3bc46bd9&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-02-03 15:29:16 +0100'>2020-02-03</span></td><td><a href='/guix/commit/gnu/packages/libbsd.scm?id=effd1422af81b210682a22f34858c5c69f7a1ba7'>gnu: libbsd: Do not build the static library.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/libbsd.scm (libbsd)[arguments]: New field.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2019-12-05 17:59:00 +0100'>2019-12-05</span></td><td><a href='/guix/commit/gnu/packages/libbsd.scm?id=abd5124417bda96ddd0a73a198465b357940a5d5'>gnu: libbsd: Update to 0.10.0.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/libbsd.scm (libbsd): Update to 0.10.0.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-06-12 18:30:18 +0200'>2018-06-12</span></td><td><a href='/guix/commit/gnu/packages/libbsd.scm?id=53411dfcd6e696fc4aea11c70d411db5300ac5e2'>gnu: libbsd: Update to 0.9.1.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/libbsd.scm (libbsd): Update to 0.9.1.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-02-20 16:01:46 +0100'>2018-02-20</span></td><td><a href='/guix/commit/gnu/packages/libbsd.scm?id=cb4a178b200a0efa2b27f71cd1421cb7f92911f3'>gnu: libbsd: Update to 0.8.7.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/libbsd.scm (libbsd): Update to 0.8.7.
</span></span></td><td>Marius Bakke</td></tr>