gitweb: Convert string to internal form before chopping in chop_str

Fix chop_str not to cut in middle of utf8 multibyte chars. Without
this fix at least author name in short log may cut in middle of a
multibyte char. When the result comes to esc_html to_utf8 is called
again, which doesn't find valid utf8 and decodes using
$fallback_encoding making it even worse.

This also have the nice side effect that it actually tries to show the
first 10 _characters_, not the number of characters that happened to fit
into 10 bytes.
Signed-off-by: NAnders Waldenborg <anders@0x63.nu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -866,6 +866,10 @@ sub chop_str {
 	my $add_len = shift || 10;
 	my $where = shift || 'right'; # 'left' | 'center' | 'right'
 
+	# Make sure perl knows it is utf8 encoded so we don't
+	# cut in the middle of a utf8 multibyte char.
+	$str = to_utf8($str);
+
 	# allow only $len chars, but don't cut a word if it would fit in $add_len
 	# if it doesn't fit, cut it if it's still longer than the dots we would add
 	# remove chopped character entities entirely