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
'/guix/refs/?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>refs</a><a class='active' href='/guix/log/etc/copyright.el'>log</a><a href='/guix/tree/etc/copyright.el?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>tree</a><a href='/guix/commit/etc/copyright.el?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>commit</a><a href='/guix/diff/etc/copyright.el?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/copyright.el'>
<input type='hidden' name='id' value='0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>root</a>/<a href='/guix/log/etc?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>etc</a>/<a href='/guix/log/etc/copyright.el?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4'>copyright.el</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/etc/copyright.el?id=0ece738474b82082a1f2a2cd2ae2bc31d99de9a4&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-02-22 17:56:31 +0300'>2020-02-22</span></td><td><a href='/guix/commit/etc/copyright.el?id=9a3971143854bf877c0739fc8fdf7b945a2e3935'>etc: Add copyright.</a><span class='msg-avail'>...</span></td><td>Oleg Pykhalov</td></tr>