Regenerate invoice number on sale unsuspend if no custom format is used (#423)

application/controllers/Sales.php

@@ -511,6 +511,13 @@ class Sales extends Secure_area
 
 		return $text;
 	}
+
+	private function _is_custom_invoice_number($cust_info)
+	{
+		$invoice_number = $this->config->config['sales_invoice_format'];
+		$invoice_number = $this->_substitute_variables($invoice_number, $cust_info);
+		return $this->sale_lib->get_invoice_number() != $invoice_number;
+	}
 	
 	private function _substitute_variables($text, $cust_info)
 	{
@@ -791,6 +798,7 @@ class Sales extends Secure_area
 		$data['amount_change'] = to_currency($this->sale_lib->get_amount_due() * -1);
 		$data['employee'] = $emp_info->first_name.' '.$emp_info->last_name;
 
+		$cust_info = '';
 		if($customer_id != -1)
 		{
 			$cust_info = $this->Customer->get_info($customer_id);
@@ -804,6 +812,9 @@ class Sales extends Secure_area
 			}
 		}
 
+		$is_set = $this->_is_custom_invoice_number($cust_info);
+		$invoice_number = $is_set ? $invoice_number : NULL;
+
 		$total_payments = 0;
 
 		foreach($data['payments'] as $payment)