Allow to issue gift card refunds when cancelling whole events

src/pretix/control/forms/orders.py

@@ -554,6 +554,22 @@ class EventCancelForm(forms.Form):
                     'manual refund to-do list. Do not check if you want to refund some of the orders by offsetting '
                     'with different orders or issuing gift cards.')
     )
+    refund_as_giftcard = forms.BooleanField(
+        label=_('Refund order value to a gift card instead'),
+        widget=forms.CheckboxInput(attrs={'data-display-dependency': '#id_auto_refund'}),
+        initial=False,
+        required=False,
+        help_text='{}'
+                  '<div class="alert alert-legal">'
+                  '<strong>{}:</strong> {}'
+                  '</div>'.format(
+            _('If checked, all refunds will be issued as gift cards instead of a payment to the original payment '
+              'method. When this functionality is used, you will need to explain your customers how to access it.'),
+            _('Warning'),
+            _('Depending on your location, refunding a customer with a gift card without their consent might be '
+              'illegal. If in doubt, consult a lawyer or refrain from issuing refunds on gift cards.')
+        )
+    )
     keep_fee_fixed = forms.DecimalField(
         label=_("Keep a fixed cancellation fee"),
         max_digits=10, decimal_places=2,