[wp-trac] [WordPress Trac] #62521: HTML Processor virtual token seek does not seek to correct location

Fri Nov 22 10:14:01 UTC 2024

#62521: HTML Processor virtual token seek does not seek to correct location
--------------------------+------------------------------
 Reporter:  jonsurrell    |       Owner:  (none)
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  Awaiting Review
Component:  HTML API      |     Version:  6.7
 Severity:  normal        |  Resolution:
 Keywords:                |     Focuses:
--------------------------+------------------------------
Description changed by jonsurrell:

Old description:

> {{{#!php
> <?php
> $processor = WP_HTML_Processor::create_full_parser( 'text only' );
>
> $advance_and_log_tag = function () use ( $processor ) {
>         assert( $processor->next_tag( array( 'tag_closers' => 'visit' ) )
> );
>         echo str_repeat( '  ', $processor->get_current_depth() ) .
>                 ( $processor->is_tag_closer() ? '  /' : '' ) .
>                 $processor->get_token_name() .
>                 "\n";
> };
>
> $advance_and_log_tag();
> $advance_and_log_tag();
> $advance_and_log_tag();
> $advance_and_log_tag();
> // Now at `<BODY>` virtual token, not present in the HTML string.
> assert( 'BODY' === $processor->get_token_name() && !
> $processor->is_tag_closer() );
> assert( $processor->set_bookmark( 'apparently <BODY> open tag' ) );
> $advance_and_log_tag();
> $advance_and_log_tag();
> // Now at `</HTML>` virtual token, not present in the HTML string.
> assert( $processor->seek( 'apparently <BODY> open tag' ) );
> // Expected to return to `<BODY>` open tag.
> echo $processor->get_token_name() . "\n";
> // prints: #text
> assert( 'BODY' === $processor->get_token_name() );
> // AssertionError!
> }}}
>
> The above prints:
>
> {{{
>   HTML
>     HEAD
>     /HEAD
>     BODY
>     /BODY
>   /HTML
> #text
>
> Fatal error: Uncaught AssertionError: assert('BODY' ===
> $processor->get_token_name()) …
> }}}

New description:

 When an HTML_Processor bookmark is set at a virtual token (a node in the
 resulting document that does not correspond to an HTML token present in
 the input string), seek behavior becomes unreliable.

 For example:

 {{{#!php
 <?php
 $processor = WP_HTML_Processor::create_full_parser( 'text only' );

 $advance_and_log_tag = function () use ( $processor ) {
         assert( $processor->next_tag( array( 'tag_closers' => 'visit' ) )
 );
         echo str_repeat( '  ', $processor->get_current_depth() ) .
                 ( $processor->is_tag_closer() ? '  /' : '' ) .
                 $processor->get_token_name() .
                 "\n";
 };

 $advance_and_log_tag();
 $advance_and_log_tag();
 $advance_and_log_tag();
 $advance_and_log_tag();
 // Now at `<BODY>` virtual token, not present in the HTML string.
 assert( 'BODY' === $processor->get_token_name() && !
 $processor->is_tag_closer() );
 assert( $processor->set_bookmark( 'apparently <BODY> open tag' ) );
 $advance_and_log_tag();
 $advance_and_log_tag();
 // Now at `</HTML>` virtual token, not present in the HTML string.
 assert( $processor->seek( 'apparently <BODY> open tag' ) );
 // Expected to return to `<BODY>` open tag.
 echo $processor->get_token_name() . "\n";
 // prints: #text
 assert( 'BODY' === $processor->get_token_name() );
 // AssertionError!
 }}}

 The above prints:

 {{{
   HTML
     HEAD
     /HEAD
     BODY
     /BODY
   /HTML
 #text

 Fatal error: Uncaught AssertionError: assert('BODY' ===
 $processor->get_token_name()) …
 }}}

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Ticket URL: <https://core.trac.wordpress.org/ticket/62521#comment:3>
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