Eliminating reverse encoding in Info converter

On Fri, Aug 14, 2026 at 04:42:32PM +0200, Patrice Dumas wrote:
> The second is about easing the implementation.  We convert to UTF-8 upon
> reading and do everything in this encoding, in particular determining
> line width for cutting lines, or centering or flushing right.  In Info
> output, however, we also need to track the bytes count in the output
> encoding to fill the Info tag tables that allows to find anchors and
> nodes in Info file.  Therefore, we do the output in two phases, first
> conversion in UTF-8 and then encoding to determine bytes counts.  In
> some cases it is not easy to do it in two phases, we need to convert
> back already encoded strings to UTF-8 to do the counting.  Outputting
> in UTF-8 only would remove
> * the need to do two phases
> * the need to convert back

I don't know if it helps but I have the commit below sitting on my "git stash"
list (since 2024-01-24!).

At least at that time, I was looking at eliminating the _decode function
in Plaintext.pm (which reverses the encoding_ - so there is a chance this is
possible.  As far as I remember it was possible and I didn't make the
change because there was a very slight performance impact - that said, I
don't remember the details.  I'm not expecting anybody to make sense of
my old, incomplete patch, just posting it to demonstrate that it was a
real possibility that could be explored further.


commit e7a667239560e25fbfdedafdc453549c7527cadb
Merge: 3c25f2b54d d6c24486a0
Author: Gavin Smith <[email protected]>
Date:   2024-01-24 18:05:23 +0000

    WIP on master: 3c25f2b54d * tp/Texinfo/Convert/Plaintext.pm (process_printindex) <(outside of any node>: Call convert_line_new_context with encoding disabled.

diff --cc tp/Texinfo/Convert/Info.pm
index 04fff3f421,04fff3f421..7227d846fc
--- a/tp/Texinfo/Convert/Info.pm
+++ b/tp/Texinfo/Convert/Info.pm
@@@ -316,6 -316,6 +316,7 @@@ sub output($$
        $prefix = 'Ref';
      }
      my ($label_text, undef) = $self->node_name($label->{'root'});
++    my $label_text_encoded = $self->_stream_encode($label_text);
  
      if ($seen_anchors{$label_text}) {
        $self->plaintext_line_error($self,
@@@ -329,7 -329,7 +330,7 @@@
        $seen_anchors{$label_text} = 1;
      }
  
--    $tag_text .=  "$prefix: $label_text\x{7F}$label->{'bytes'}\n";
++    $tag_text .=  "$prefix: $label_text_encoded\x{7F}$label->{'bytes'}\n";
    }
    $tag_text .=  "\x{1F}\nEnd Tag Table\n";
  
@@@ -529,8 -529,8 +530,8 @@@ sub format_node($$
    if ($node_text =~ /,/) {
      if ($self->{'info_special_chars_warning'}) {
        $self->plaintext_line_warn($self, sprintf(__(
--                 "\@node name should not contain `,': %s"),
--                     $self->_decode($node_text)), $node->{'source_info'});
++                 "\@node name should not contain `,': %s"), $node_text),
++               $node->{'source_info'});
      }
      if ($self->{'info_special_chars_quote'}) {
        $pre_quote = "\x{7f}";
diff --cc tp/Texinfo/Convert/Plaintext.pm
index 2c7217e715,2c7217e715..544339728a
--- a/tp/Texinfo/Convert/Plaintext.pm
+++ b/tp/Texinfo/Convert/Plaintext.pm
@@@ -1001,19 -1001,19 +1001,6 @@@ sub _stream_byte_count($
    return $count_context->{'bytes'};
  }
  
--# Used occasionally for already encoded output
--sub _decode($$)
--{
--  my ($self, $encoded) = @_;
--
--  if (!$self->{'encoding_object'}) {
--    return $encoded; # probably wrong
--  } else {
--    my $decoded = $self->{'encoding_object'}->decode($encoded);
--    return $decoded;
--  }
--}
--
  # Occassionally, we need to find the width of a string after it has
  # already been encoded.  Use of this should be minimised for performance.
  sub _string_width_encoded($$)
@@@ -1466,7 -1466,7 +1453,7 @@@ sub node_name($$
                       'contents' => [$label_element]};
      my ($result, $width) = $self->convert_line_new_context($node_text,
                                      {'suppress_styles' => 1,
--                                     'no_added_eol' => 1,});
++                                     'no_added_eol' => 1,}, 1);
      $self->{'node_names_text'}->{$node}
        = {'text' => _normalize_top_node($result),
           'width' => $width };
@@@ -1705,7 -1705,7 +1692,7 @@@ sub process_printindex($$;$
            $node_name = $pre_quote . $node_name . $post_quote;
          }
        }
--      _stream_output_encoded($self, $node_name);
++      _stream_output($self, $node_name);
        $line_width += $width;
      }
      _stream_output($self, '.');