Refactor: Rename variable for comparison operator in get_adjacent_post function.

 improve code clarity by renaming the `$op` variable to `$comparison_operator`,

Author: ramonjd

src/wp-includes/link-template.php

@@ -1939,8 +1939,8 @@ function get_adjacent_post( $in_same_term = false, $excluded_terms = '', $previo
 		$where .= " AND p.post_status = 'publish'";
 	}
 
-	$op    = $previous ? '<' : '>';
-	$order = $previous ? 'DESC' : 'ASC';
+	$comparison_operator = $previous ? '<' : '>';
+	$order               = $previous ? 'DESC' : 'ASC';
 
 	/**
 	 * Filters the JOIN clause in the SQL for an adjacent post query.
@@ -1965,7 +1965,7 @@ function get_adjacent_post( $in_same_term = false, $excluded_terms = '', $previo
 	$join = apply_filters( "get_{$adjacent}_post_join", $join, $in_same_term, $excluded_terms, $taxonomy, $post );
 
 	// Prepare the where clause for the adjacent post query.
-	$where_prepared = $wpdb->prepare( "WHERE (p.post_date $op %s OR (p.post_date = %s AND p.ID $op %d)) AND p.post_type = %s $where", $current_post_date, $current_post_date, $post->ID, $post->post_type ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $op is a string literal, either '<' or '>'.
+	$where_prepared = $wpdb->prepare( "WHERE (p.post_date $comparison_operator %s OR (p.post_date = %s AND p.ID $comparison_operator %d)) AND p.post_type = %s $where", $current_post_date, $current_post_date, $post->ID, $post->post_type ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- $comparison_operator is a string literal, either '<' or '>'.
 
 	/**
 	 * Filters the WHERE clause in the SQL for an adjacent post query.