WP_Customize_Manager::preserve_insert_changeset_post_content()
Method: Preserves the initial JSON post_content passed to save into the post.
Source: wp-includes/class-wp-customize-manager.php:3028
wp_insert_attachment_data
Filter Hook: Filters attachment post data before it is updated in or added to the database.
Source: wp-includes/post.php:4174
wp_insert_post_data
Filter Hook: Filters slashed post data just before it is inserted into the database.
Source: wp-includes/post.php:4189