We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Promotional code field and button overlap each other.
In the checkout process:
<img width="465" alt="zrzut ekranu 2018-01-10 o 10 02 22" src="https://user-images.githubusercontent.com/1561204/34765559-24865056-f5f2-11e7-9e2a-d0ff639e7a79.png">


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `saleor/discount/forms.py`
Content:
```
1 from datetime import date
2 
3 from django import forms
4 from django.utils.encoding import smart_text
5 from django.utils.translation import pgettext_lazy
6 
7 from .models import NotApplicable, Voucher
8 
9 
10 class VoucherField(forms.ModelChoiceField):
11 
12     default_error_messages = {
13         'invalid_choice': pgettext_lazy(
14             'voucher', pgettext_lazy(
15                 'Voucher form error', 'Discount code incorrect or expired')),
16     }
17 
18 
19 class CheckoutDiscountForm(forms.Form):
20 
21     voucher = VoucherField(
22         queryset=Voucher.objects.none(),
23         to_field_name='code',
24         label=pgettext_lazy(
25             'Checkout discount form label for voucher field',
26             'Gift card or discount code'),
27         widget=forms.TextInput)
28 
29     def __init__(self, *args, **kwargs):
30         self.checkout = kwargs.pop('checkout')
31         initial = kwargs.get('initial', {})
32         if 'voucher' not in initial:
33             initial['voucher'] = self.checkout.voucher_code
34         kwargs['initial'] = initial
35         super().__init__(*args, **kwargs)
36         self.fields['voucher'].queryset = Voucher.objects.active(
37             date=date.today())
38 
39     def clean(self):
40         cleaned_data = super().clean()
41         if 'voucher' in cleaned_data:
42             voucher = cleaned_data['voucher']
43             try:
44                 discount = voucher.get_discount_for_checkout(self.checkout)
45                 cleaned_data['discount'] = discount
46             except NotApplicable as e:
47                 self.add_error('voucher', smart_text(e))
48         return cleaned_data
49 
50     def apply_discount(self):
51         discount = self.cleaned_data['discount']
52         voucher = self.cleaned_data['voucher']
53         self.checkout.discount = discount
54         self.checkout.voucher_code = voucher.code
55
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/saleor/discount/forms.py b/saleor/discount/forms.py
--- a/saleor/discount/forms.py
+++ b/saleor/discount/forms.py
@@ -21,7 +21,7 @@
     voucher = VoucherField(
         queryset=Voucher.objects.none(),
         to_field_name='code',
-        label=pgettext_lazy(
+        help_text=pgettext_lazy(
             'Checkout discount form label for voucher field',
             'Gift card or discount code'),
         widget=forms.TextInput)

{"golden_diff": "diff --git a/saleor/discount/forms.py b/saleor/discount/forms.py\n--- a/saleor/discount/forms.py\n+++ b/saleor/discount/forms.py\n@@ -21,7 +21,7 @@\n     voucher = VoucherField(\n         queryset=Voucher.objects.none(),\n         to_field_name='code',\n-        label=pgettext_lazy(\n+        help_text=pgettext_lazy(\n             'Checkout discount form label for voucher field',\n             'Gift card or discount code'),\n         widget=forms.TextInput)\n", "issue": "Promotional code field and button overlap each other.\nIn the checkout process:\r\n<img width=\"465\" alt=\"zrzut ekranu 2018-01-10 o 10 02 22\" src=\"https://user-images.githubusercontent.com/1561204/34765559-24865056-f5f2-11e7-9e2a-d0ff639e7a79.png\">\r\n\n", "before_files": [{"content": "from datetime import date\n\nfrom django import forms\nfrom django.utils.encoding import smart_text\nfrom django.utils.translation import pgettext_lazy\n\nfrom .models import NotApplicable, Voucher\n\n\nclass VoucherField(forms.ModelChoiceField):\n\n    default_error_messages = {\n        'invalid_choice': pgettext_lazy(\n            'voucher', pgettext_lazy(\n                'Voucher form error', 'Discount code incorrect or expired')),\n    }\n\n\nclass CheckoutDiscountForm(forms.Form):\n\n    voucher = VoucherField(\n        queryset=Voucher.objects.none(),\n        to_field_name='code',\n        label=pgettext_lazy(\n            'Checkout discount form label for voucher field',\n            'Gift card or discount code'),\n        widget=forms.TextInput)\n\n    def __init__(self, *args, **kwargs):\n        self.checkout = kwargs.pop('checkout')\n        initial = kwargs.get('initial', {})\n        if 'voucher' not in initial:\n            initial['voucher'] = self.checkout.voucher_code\n        kwargs['initial'] = initial\n        super().__init__(*args, **kwargs)\n        self.fields['voucher'].queryset = Voucher.objects.active(\n            date=date.today())\n\n    def clean(self):\n        cleaned_data = super().clean()\n        if 'voucher' in cleaned_data:\n            voucher = cleaned_data['voucher']\n            try:\n                discount = voucher.get_discount_for_checkout(self.checkout)\n                cleaned_data['discount'] = discount\n            except NotApplicable as e:\n                self.add_error('voucher', smart_text(e))\n        return cleaned_data\n\n    def apply_discount(self):\n        discount = self.cleaned_data['discount']\n        voucher = self.cleaned_data['voucher']\n        self.checkout.discount = discount\n        self.checkout.voucher_code = voucher.code\n", "path": "saleor/discount/forms.py"}], "after_files": [{"content": "from datetime import date\n\nfrom django import forms\nfrom django.utils.encoding import smart_text\nfrom django.utils.translation import pgettext_lazy\n\nfrom .models import NotApplicable, Voucher\n\n\nclass VoucherField(forms.ModelChoiceField):\n\n    default_error_messages = {\n        'invalid_choice': pgettext_lazy(\n            'voucher', pgettext_lazy(\n                'Voucher form error', 'Discount code incorrect or expired')),\n    }\n\n\nclass CheckoutDiscountForm(forms.Form):\n\n    voucher = VoucherField(\n        queryset=Voucher.objects.none(),\n        to_field_name='code',\n        help_text=pgettext_lazy(\n            'Checkout discount form label for voucher field',\n            'Gift card or discount code'),\n        widget=forms.TextInput)\n\n    def __init__(self, *args, **kwargs):\n        self.checkout = kwargs.pop('checkout')\n        initial = kwargs.get('initial', {})\n        if 'voucher' not in initial:\n            initial['voucher'] = self.checkout.voucher_code\n        kwargs['initial'] = initial\n        super().__init__(*args, **kwargs)\n        self.fields['voucher'].queryset = Voucher.objects.active(\n            date=date.today())\n\n    def clean(self):\n        cleaned_data = super().clean()\n        if 'voucher' in cleaned_data:\n            voucher = cleaned_data['voucher']\n            try:\n                discount = voucher.get_discount_for_checkout(self.checkout)\n                cleaned_data['discount'] = discount\n            except NotApplicable as e:\n                self.add_error('voucher', smart_text(e))\n        return cleaned_data\n\n    def apply_discount(self):\n        discount = self.cleaned_data['discount']\n        voucher = self.cleaned_data['voucher']\n        self.checkout.discount = discount\n        self.checkout.voucher_code = voucher.code\n", "path": "saleor/discount/forms.py"}]}