Bulk Edit: addslashes() expects parameter 1 to be string..

Anyone seen this recently on Products Bulk Edit?
This is on WooCommerce 3.1 on php7.0.

I haven’t successfully reproduced on vanilla test environment, however this is with Simple products and as far as I read it, all the call stack points to woocommerce:

`
[04-Jul-2017 15:55:54 UTC] PHP Warning: addslashes() expects parameter 1 to be string, object given in wp-includes/formatting.php on line 4868
[04-Jul-2017 15:55:54 UTC] PHP Stack trace:
[04-Jul-2017 15:55:54 UTC] PHP 1. {main}() wp-admin/edit.php:0
[04-Jul-2017 15:55:54 UTC] PHP 2. bulk_edit_posts($post_data = *uninitialized*) wp-admin/edit.php:155
[04-Jul-2017 15:55:54 UTC] PHP 3. wp_update_post($postarr = *uninitialized*, $wp_error = *uninitialized*) wp-admin/includes/post.php:568
[04-Jul-2017 15:55:54 UTC] PHP 4. wp_insert_post($postarr = *uninitialized*, $wp_error = *uninitialized*) wp-includes/post.php:3583
[04-Jul-2017 15:55:54 UTC] PHP 5. do_action($tag = *uninitialized*, $arg = *uninitialized*, *uninitialized*, *uninitialized*) wp-includes/post.php:3510
[04-Jul-2017 15:55:54 UTC] PHP 6. WP_Hook->do_action($args = *uninitialized*) wp-includes/plugin.php:453
[04-Jul-2017 15:55:54 UTC] PHP 7. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) wp-includes/class-wp-hook.php:323
[04-Jul-2017 15:55:54 UTC] PHP 8. WC_Admin_Post_Types->bulk_and_quick_edit_hook($post_id = *uninitialized*, $post = *uninitialized*) wp-includes/class-wp-hook.php:300
[04-Jul-2017 15:55:54 UTC] PHP 9. do_action($tag = *uninitialized*, $arg = *uninitialized*, *uninitialized*) wp-content/plugins/woocommerce/includes/admin/class-wc-admin-post-types.php:872
[04-Jul-2017 15:55:54 UTC] PHP 10. WP_Hook->do_action($args = *uninitialized*) wp-includes/plugin.php:453
[04-Jul-2017 15:55:54 UTC] PHP 11. WP_Hook->apply_filters($value = *uninitialized*, $args = *uninitialized*) wp-includes/class-wp-hook.php:323
[04-Jul-2017 15:55:54 UTC] PHP 12. WC_Admin_Post_Types->bulk_and_quick_edit_save_post($post_id = *uninitialized*, $post = *uninitialized*) wp-includes/class-wp-hook.php:298
[04-Jul-2017 15:55:54 UTC] PHP 13. WC_Admin_Post_Types->bulk_edit_save($post_id = *uninitialized*, $product = *uninitialized*) wp-content/plugins/woocommerce/includes/admin/class-wc-admin-post-types.php:921
[04-Jul-2017 15:55:54 UTC] PHP 14. WC_Product->save() wp-content/plugins/woocommerce/includes/admin/class-wc-admin-post-types.php:1287
[04-Jul-2017 15:55:54 UTC] PHP 15. WC_Data_Store->update($data = *uninitialized*) wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-product.php:1292
[04-Jul-2017 15:55:54 UTC] PHP 16. WC_Product_Data_Store_CPT->update($product = *uninitialized*) wp-content/plugins/woocommerce/includes/class-wc-data-store.php:167
[04-Jul-2017 15:55:54 UTC] PHP 17. WC_Data->save_meta_data() wp-content/plugins/woocommerce/includes/data-stores/class-wc-product-data-store-cpt.php:166
[04-Jul-2017 15:55:54 UTC] PHP 18. WC_Data_Store->update_meta(*uninitialized*, *uninitialized*) wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-data.php:484
[04-Jul-2017 15:55:54 UTC] PHP 19. WC_Data_Store->__call($method = *uninitialized*, $parameters = *uninitialized*) wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-data.php:484
[04-Jul-2017 15:55:54 UTC] PHP 20. WC_Data_Store_WP->update_meta($object = *uninitialized*, $meta = *uninitialized*) wp-content/plugins/woocommerce/includes/class-wc-data-store.php:196
[04-Jul-2017 15:55:54 UTC] PHP 21. wp_slash($value = *uninitialized*) wp-content/plugins/woocommerce/includes/data-stores/class-wc-data-store-wp.php:114
[04-Jul-2017 15:55:54 UTC] PHP 22. wp_slash($value = *uninitialized*) wp-includes/formatting.php:4866
[04-Jul-2017 15:55:54 UTC] PHP 23. addslashes(*uninitialized*) wp-includes/formatting.php:4868
`

Symptom is bulk update is slow, cpu intensive, with at least 1 warning like this for each row updated. Update appears to succeed but visually may fail and blow up session and return admin to home page, and require re-login to continue editing..