首先是代码：

function itsme_better_editions( $query ) {
    if ( $query->is_category() && $query->is_main_query() ) {
        $query->set( \'post_type\', array( \'post\' ) );

        // Get current tax query
        $tax_query = $query->get( \'tax_query\' );

        $tax_query[\'relation\'] = \'OR\';

        $tax_query[] = array(
            \'taxonomy\' => \'category\',
            \'field\' => \'slug\',
            \'terms\' => \'intl\',
            \'operator\' => \'IN\'
        );

        $query->set( \'tax_query\', $tax_query );
    }
    return $query;
}
add_filter( \'pre_get_posts\', \'itsme_better_editions\' );

我觉得一切都很好，除了$query->get( \'tax_query\' ); 似乎返回空或不是数组，即返回以下条件true:

if( !empty($tax_query) || is_array($tax_query) ) {
   // whatever
}

This is breaking stuff, I later realized.

档案中显示了正确的帖子，即列出了属于当前类别或“国际（intl）”类别的帖子。这就是我想要的。

但术语对象指向“intl”类别（标签存档中也会发生同样的情况；它指向的不是当前标签的术语对象，而是“intl”类别）。例如，如果我访问“UK（UK）”类别档案，则会显示“International”而不是“UK”。

这只是我迄今为止注意到的问题之一；我不知道还有什么坏了。

功能有什么问题？

<小时>PS: 因为$query->get( \'tax_query\' ); 如果返回的是空数组或不是数组，我必须手动填充它，如下所示：

/*
 * Show posts assigned to \'International (intl)\' Edition
 * in all editions.
 */
function itsme_better_editions( $query ) {
    if( $query->is_category() && $query->is_main_query() ) {

        $query->set( \'post_type\', array( \'post\' ) );

        // NOT WORKING!!!
        //$tax_query = $query->get( \'tax_query\' );

        // Equivalent of original `$tax_query` START.
        $get_original_category = get_query_var( \'category_name\' );
        $original_category = get_term_by( \'slug\', $get_original_category, \'category\' );
        if( $original_category && !is_wp_error( $original_category ) ) {
            $itsme_original_category = $get_original_category;
        }

        $tax_query[] = array(
            \'taxonomy\' => \'category\',
            \'field\' => \'slug\',
            \'terms\' => $original_category,
            \'operator\' => \'IN\'
        );
        // Equivalent of original `$tax_query` END.

        $tax_query[\'relation\'] = \'OR\';

        $tax_query[] = array(
            \'taxonomy\' => \'category\',
            \'field\' => \'slug\',
            \'terms\' => \'intl\',
            \'operator\' => \'IN\'
        );

        $query->set( \'tax_query\', $tax_query );
    }
    return $query;
}
add_filter( \'pre_get_posts\', \'itsme_better_editions\' );

或者简单地替换查询，如下所示：

/*
 * Show posts assigned to \'International (intl)\' Edition
 * in all editions.
 */
function itsme_better_editions( $query ) {
    if( $query->is_category() && $query->is_main_query() ) {

        // Get original/actual category of the category archive
        $get_original_category = get_query_var( \'category_name\' );
        $original_category = get_term_by( \'slug\', $get_original_category, \'category\' );
        if( $original_category && !is_wp_error( $original_category ) ) {
            $itsme_original_category = $get_original_category;
        }

        if( isset($itsme_original_category) ) {

            $query->set( \'post_type\', array( \'post\' ) );

            $query->set( "category_name", "{$itsme_original_category}, intl" );

        }

    }
}
add_action( \'pre_get_posts\', \'itsme_better_editions\' );

这是可行的，但我为什么要这样做呢？不是的$tax_query = $query->get( \'tax_query\' ); 应该归还原件tax_query?

如何重现问题。创建两个类别：英国（UK）和国际（intl）。创建2个帖子，并仅将其分配给“英国”；1仅在“国际”项下。

现在example.com/category/uk/ 显示2个帖子；和example.com/category/intl/ 显示1。

现在在主题函数中添加第一个函数（第一个代码块）。php，并访问example.com/category/uk/. 您将看到页面的类别名称(<?php single_cat_title(); ?>) 显示为“国际”。Why? 如果我没有错，因为$query->get（\'tax\\u query\'）；似乎返回空，而不是数组。

3、替换函数中的函数。具有上述第二个或第三个函数的php。现在，一切都应该按预期进行。

PS: 是的，我自己用默认主题（213）做了这个测试，它仍然存在。所以你可以很好地重现这个问题。

function itsme_better_editions( $query ) {

  if ( $query->is_category() && $query->is_main_query() ) {

    $query->set( \'post_type\', array( \'post\' ) );

    $tax_query_obj = clone $query->tax_query;

    $tax_query_obj->queries[] = array(
      \'taxonomy\' => \'category\',
      \'field\' => \'slug\',
      \'terms\' => \'intl\',
      \'operator\' => \'IN\'
    );

    $tax_query = array(\'relation\' => \'OR\');

    foreach ( $tax_query_obj->queries as $q ) {
      $tax_query[] = $q;
    }

    $query->set(\'tax_query\', $tax_query);
  }

}

add_action( \'pre_get_posts\', \'itsme_better_editions\' );

function itsme_better_editions( $query ) {
  $query->set( \'post_type\', array( \'post\' ) );

  // Get current tax query
  $tax_query = $query->get( \'tax_query\' );
  var_dump($tax_query); die;
}
add_action( \'pre_get_posts\', \'itsme_better_editions\' );

$t = new WP_Query(
  array(
    \'post_type\' => \'post\',
    \'tax_query\' => array(
      array(
        \'taxonomy\' => \'category\',
        \'field\' => \'slug\',
        \'terms\' => \'intl\',
        \'operator\' => \'IN\'
      )
    )
  )
);