Taxonomy: In `wp_insert_term()`, handle an error if writing to the `term_taxonomy` table fails.

This complements the check for successful writing to the `terms` table, added in [7430].

Props mbabker.
Fixes #47313.
Built from https://develop.svn.wordpress.org/trunk@45362


git-svn-id: http://core.svn.wordpress.org/trunk@45173 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/taxonomy.php

@@ -2276,7 +2276,11 @@ function wp_insert_term( $term, $taxonomy, $args = array() ) {
 			'term_taxonomy_id' => $tt_id,
 		);
 	}
-	$wpdb->insert( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent' ) + array( 'count' => 0 ) );
+
+	if ( false === $wpdb->insert( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent' ) + array( 'count' => 0 ) ) ) {
+		return new WP_Error( 'db_insert_error', __( 'Could not insert term taxonomy into the database.' ), $wpdb->last_error );
+	}
+
 	$tt_id = (int) $wpdb->insert_id;
 
 	/*

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-45357';
+$wp_version = '5.3-alpha-45362';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.