Handle root taxonomy separately

src/wp-includes/class-wp-query.php

@@ -962,7 +962,11 @@ public function parse_query( $query = '' ) {
 							$this->is_tag = true;
 							break;
 						default:
-							$this->is_tax = true;
+							if ( ! empty( $tax_query['terms'] ) ) {
+								$this->is_tax = true;
+							} else {
+								$this->is_tax_without_term = true;
+							}
 					}
 				}
 			}
@@ -4250,6 +4254,44 @@ public function is_tag( $tag = '' ) {
 		return false;
 	}
 
+	/**
+	 * Determines whether the query is for an existing custom taxonomy root archive page.
+	 *
+	 * If the $taxonomy parameter is specified, this function will additionally
+	 * check if the query is for that specific $taxonomy.
+	 *
+	 * @since 6.8.0
+	 *
+	 * @global WP_Taxonomy[] $wp_taxonomies Registered taxonomies.
+	 *
+	 * @param string|string[] $taxonomy Optional. Taxonomy slug or slugs to check against.
+	 *                                  Default empty.
+	 * @return bool Whether the query is for an existing custom taxonomy root archive page.
+	 *              True for custom taxonomy root archive pages, false for built-in taxonomies
+	 *              (category and tag archives).
+	 */
+	public function is_tax_without_term( $taxonomy = '' ) {
+		global $wp_taxonomies;
+
+		if ( ! $this->is_tax_without_term ) {
+			return false;
+		}
+
+		if ( empty( $taxonomy ) ) {
+			return true;
+		}
+
+		$queried_object = $this->get_queried_object();
+		$tax_array      = array_intersect( array_keys( $wp_taxonomies ), (array) $taxonomy );
+
+		// Check that the taxonomy matches.
+		if ( ! ( isset( $queried_object->name ) && count( $tax_array ) && in_array( $queried_object->name, $tax_array, true ) ) ) {
+			return false;
+		}
+
+		return true;
+	}
+
 	/**
 	 * Determines whether the query is for an existing custom taxonomy archive page.
 	 *

src/wp-includes/general-template.php

@@ -1758,19 +1758,22 @@ function get_the_archive_title() {
 	} elseif ( is_post_type_archive() ) {
 		$title  = post_type_archive_title( '', false );
 		$prefix = _x( 'Archives:', 'post type archive title prefix' );
+	} elseif ( is_tax_without_term() ) {
+		$queried_object = get_queried_object();
+		if ( $queried_object ) {
+			$title  = $queried_object->labels->singular_name;
+			$prefix = _x( 'Archives:', 'taxonomy archive title prefix' );
+		}
 	} elseif ( is_tax() ) {
 		$queried_object = get_queried_object();
-		if ( $queried_object instanceof WP_Term ) {
+		if ( $queried_object ) {
 			$tax    = get_taxonomy( $queried_object->taxonomy );
 			$title  = single_term_title( '', false );
 			$prefix = sprintf(
 				/* translators: %s: Taxonomy singular name. */
 				_x( '%s:', 'taxonomy term archive title prefix' ),
 				$tax->labels->singular_name
 			);
-		} elseif ( $queried_object instanceof WP_Taxonomy ) {
-			$title  = $queried_object->labels->singular_name;
-			$prefix = _x( 'Archives:', 'taxonomy archive title prefix' );
 		}
 	}
 

src/wp-includes/query.php

@@ -308,6 +308,37 @@ function is_tag( $tag = '' ) {
 	return $wp_query->is_tag( $tag );
 }
 
+/**
+ * Determines whether the query is for an existing custom taxonomy root archive page.
+ *
+ * If the $taxonomy parameter is specified, this function will additionally
+ * check if the query is for that specific $taxonomy.
+ *
+ * For more information on this and similar theme functions, check out
+ * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
+ * Conditional Tags} article in the Theme Developer Handbook.
+ *
+ * @since 6.8.0
+ *
+ * @global WP_Query $wp_query WordPress Query object.
+ *
+ * @param string|string[] $taxonomy Optional. Taxonomy slug or slugs to check against.
+ *                                  Default empty.
+ * @return bool Whether the query is for an existing custom taxonomy root archive page.
+ *              True for custom taxonomy root archive pages, false for built-in taxonomies
+ *              (category and tag archives).
+ */
+function is_tax_without_term( $taxonomy = '' ) {
+	global $wp_query;
+
+	if ( ! isset( $wp_query ) ) {
+		_doing_it_wrong( __FUNCTION__, __( 'Conditional query tags do not work before the query is run. Before then, they always return false.' ), '3.1.0' );
+		return false;
+	}
+
+	return $wp_query->is_tax_without_term( $taxonomy );
+}
+
 /**
  * Determines whether the query is for an existing custom taxonomy archive page.
  *

src/wp-includes/template-loader.php

@@ -62,6 +62,7 @@
 		'is_home'              => 'get_home_template',
 		'is_privacy_policy'    => 'get_privacy_policy_template',
 		'is_post_type_archive' => 'get_post_type_archive_template',
+		'is_tax_without_term'  => 'get_root_taxonomy_template',
 		'is_tax'               => 'get_taxonomy_template',
 		'is_attachment'        => 'get_attachment_template',
 		'is_single'            => 'get_single_template',

src/wp-includes/template.php

@@ -317,6 +317,45 @@ function get_tag_template() {
 	return get_query_template( 'tag', $templates );
 }
 
+/**
+ * Retrieves path of custom taxonomy root template in current or parent template.
+ *
+ * The hierarchy for this template looks like:
+ *
+ * 1. root-taxonomy-{taxonomy_slug}.php
+ * 2. taxonomy-{taxonomy_slug}.php
+ * 3. root-taxonomy.php
+ * 4. taxonomy.php
+ *
+ * An example of this is:
+ *
+ * 1. root-taxonomy-location.php
+ * 2. taxonomy-location.php
+ * 3. root-taxonomy.php
+ * 4. taxonomy.php
+ *
+ * The template hierarchy and template path are filterable via the {@see '$type_template_hierarchy'}
+ * and {@see '$type_template'} dynamic hooks, where `$type` is 'taxonomy'.
+ *
+ * @since 6.8.0
+ *
+ * @see get_query_template()
+ *
+ * @return string Full path to custom taxonomy term template file.
+ */
+function get_root_taxonomy_template() {
+	$tax = get_queried_object();
+
+	$templates = array();
+
+	$templates[] = "root-taxonomy-$taxonomy.php";
+	$templates[] = "taxonomy-$taxonomy.php";
+	$templates[] = 'root-taxonomy.php';
+	$templates[] = 'taxonomy.php';
+
+	return get_query_template( 'taxonomy', $templates );
+}
+
 /**
  * Retrieves path of custom taxonomy term template in current or parent template.
  *
@@ -344,12 +383,11 @@ function get_tag_template() {
  * @return string Full path to custom taxonomy term template file.
  */
 function get_taxonomy_template() {
-	$term_or_tax = get_queried_object();
+	$term = get_queried_object();
 
 	$templates = array();
 
-	if ( $term_or_tax instanceof WP_Term && ! empty( $term_or_tax->slug ) ) {
-		$term     = $term_or_tax;
+	if ( ! empty( $term->slug ) ) {
 		$taxonomy = $term->taxonomy;
 
 		$slug_decoded = urldecode( $term->slug );
@@ -359,9 +397,6 @@ function get_taxonomy_template() {
 
 		$templates[] = "taxonomy-$taxonomy-{$term->slug}.php";
 		$templates[] = "taxonomy-$taxonomy.php";
-	} elseif ( $term_or_tax instanceof WP_Taxonomy ) {
-		$taxonomy    = $term_or_tax->name;
-		$templates[] = "taxonomy-$taxonomy.php";
 	}
 	$templates[] = 'taxonomy.php';