Submit a Delivery Note if Delivery Note is mandatory to create Sales Invoice

[saurabh6790]

WN-SUP27011

Traceback (most recent call last):
  File "/home/frappe/benches/bench-2017-08-16/apps/erpnext_shopify/erpnext_shopify/sync_orders.py", line 22, in sync_shopify_orders
    create_order(shopify_order, shopify_settings)
  File "/home/frappe/benches/bench-2017-08-16/apps/erpnext_shopify/erpnext_shopify/sync_orders.py", line 54, in create_order
    create_sales_invoice(shopify_order, shopify_settings, so)
  File "/home/frappe/benches/bench-2017-08-16/apps/erpnext_shopify/erpnext_shopify/sync_orders.py", line 100, in create_sales_invoice
    si.submit()
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 741, in submit
    self._submit()
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 730, in _submit
    self.save()
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 230, in save
    return self._save(*args, **kwargs)
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 253, in _save
    self.insert()
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 192, in insert
    self.run_before_save_methods()
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 775, in run_before_save_methods
    self.run_method("validate")
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 666, in run_method
    out = Document.hook(fn)(self, *args, **kwargs)
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 887, in composer
    return composed(self, method, *args, **kwargs)
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 870, in runner
    add_to_return_value(self, fn(self, *args, **kwargs))
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/model/document.py", line 660, in <lambda>
    fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs)
  File "/home/frappe/benches/bench-2017-08-16/apps/erpnext/erpnext/accounts/doctype/sales_invoice/sales_invoice.py", line 60, in validate
    self.so_dn_required()
  File "/home/frappe/benches/bench-2017-08-16/apps/erpnext/erpnext/accounts/doctype/sales_invoice/sales_invoice.py", line 412, in so_dn_required
    msgprint(_("{0} is mandatory for Item {1}").format(i,d.item_code), raise_exception=1)
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/__init__.py", line 309, in msgprint
    _raise_exception()
  File "/home/frappe/benches/bench-2017-08-16/apps/frappe/frappe/__init__.py", line 284, in _raise_exception
    raise ValidationError(encode(msg))
ValidationError: Delivery Note is mandatory for Item PGL-61245