prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  Red input fields on first page load
  When loading some pages, input fields are redish, suggesting there where validation errors, but there was not input submit yet.
  ![screenshot from 2018-05-16 15-40-43](https://user-images.githubusercontent.com/2066372/40120463-8dadcf06-591f-11e8-966b-0ab68e153da8.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: `meinberlin/apps/users/fields.py`
  Content:
  ```
  1 import re
  2 
  3 from django import forms
  4 from django.core.exceptions import ValidationError
  5 from django.core.validators import EmailValidator
  6 from django.forms import widgets
  7 from django.utils.translation import ugettext_lazy as _
  8 
  9 
  10 class CommaSeparatedEmailField(forms.Field):
  11     email_validator = EmailValidator(
  12         message=_('Please enter correct email addresses, separated by '
  13                   'commas.')
  14     )
  15 
  16     widget = widgets.TextInput(attrs={
  17         'placeholder': 'maria@example.com, peter@example.com, '
  18                        'nicola@example.com,…'
  19     })
  20 
  21     def to_python(self, value):
  22         if not value:
  23             return []
  24 
  25         emails = []
  26         for email in value.split(','):
  27             email = email.strip()
  28             self.email_validator(email)
  29             emails.append(email)
  30 
  31         return emails
  32 
  33 
  34 class EmailFileField(forms.FileField):
  35     """Extract emails from uploaded text files."""
  36 
  37     widget = widgets.FileInput
  38     # Find possible email strings. Emails may be quoted and separated by
  39     # whitespaces, commas, semicolons or < and >.
  40     email_regex = re.compile(r'[^\s;,"\'<]+@[^\s;,"\'>]+\.[a-z]{2,}')
  41     email_validator = EmailValidator()
  42 
  43     def clean(self, data, initial=None):
  44         file = super().clean(data, initial)
  45         return self._extract_emails(file)
  46 
  47     def _extract_emails(self, file):
  48         if not file:
  49             return []
  50 
  51         emails = []
  52         for byteline in file:
  53             # As it is difficult to guess the correct encoding of a file,
  54             # email addresses are restricted to contain only ascii letters.
  55             # This works for every encoding which is a superset of ascii like
  56             # utf-8 and latin-1. Non ascii chars are simply ignored.
  57             line = byteline.decode('ascii', 'ignore')
  58             for match in self.email_regex.finditer(line):
  59                 email = match.group(0)
  60                 if self.is_valid_email(email):
  61                     emails.append(email)
  62         return emails
  63 
  64     def is_valid_email(self, email):
  65         try:
  66             self.email_validator(email)
  67             return True
  68         except ValidationError:
  69             return False
  70
  ```
  --- 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()
  
  ```
  
golden_diff: diff --git a/meinberlin/apps/users/fields.py b/meinberlin/apps/users/fields.py
  --- a/meinberlin/apps/users/fields.py
  +++ b/meinberlin/apps/users/fields.py
  @@ -14,8 +14,7 @@
       )
   
       widget = widgets.TextInput(attrs={
  -        'placeholder': 'maria@example.com, peter@example.com, '
  -                       'nicola@example.com,…'
  +        'placeholder': 'maria@example.com, peter@example.com,…'
       })
   
       def to_python(self, value):
  
verification_info: {"golden_diff": "diff --git a/meinberlin/apps/users/fields.py b/meinberlin/apps/users/fields.py\n--- a/meinberlin/apps/users/fields.py\n+++ b/meinberlin/apps/users/fields.py\n@@ -14,8 +14,7 @@\n     )\n \n     widget = widgets.TextInput(attrs={\n-        'placeholder': 'maria@example.com, peter@example.com, '\n-                       'nicola@example.com,\u2026'\n+        'placeholder': 'maria@example.com, peter@example.com,\u2026'\n     })\n \n     def to_python(self, value):\n", "issue": "Red input fields on first page load\nWhen loading some pages, input fields are redish, suggesting there where validation errors, but there was not input submit yet.\r\n![screenshot from 2018-05-16 15-40-43](https://user-images.githubusercontent.com/2066372/40120463-8dadcf06-591f-11e8-966b-0ab68e153da8.png)\r\n\n", "before_files": [{"content": "import re\n\nfrom django import forms\nfrom django.core.exceptions import ValidationError\nfrom django.core.validators import EmailValidator\nfrom django.forms import widgets\nfrom django.utils.translation import ugettext_lazy as _\n\n\nclass CommaSeparatedEmailField(forms.Field):\n    email_validator = EmailValidator(\n        message=_('Please enter correct email addresses, separated by '\n                  'commas.')\n    )\n\n    widget = widgets.TextInput(attrs={\n        'placeholder': 'maria@example.com, peter@example.com, '\n                       'nicola@example.com,\u2026'\n    })\n\n    def to_python(self, value):\n        if not value:\n            return []\n\n        emails = []\n        for email in value.split(','):\n            email = email.strip()\n            self.email_validator(email)\n            emails.append(email)\n\n        return emails\n\n\nclass EmailFileField(forms.FileField):\n    \"\"\"Extract emails from uploaded text files.\"\"\"\n\n    widget = widgets.FileInput\n    # Find possible email strings. Emails may be quoted and separated by\n    # whitespaces, commas, semicolons or < and >.\n    email_regex = re.compile(r'[^\\s;,\"\\'<]+@[^\\s;,\"\\'>]+\\.[a-z]{2,}')\n    email_validator = EmailValidator()\n\n    def clean(self, data, initial=None):\n        file = super().clean(data, initial)\n        return self._extract_emails(file)\n\n    def _extract_emails(self, file):\n        if not file:\n            return []\n\n        emails = []\n        for byteline in file:\n            # As it is difficult to guess the correct encoding of a file,\n            # email addresses are restricted to contain only ascii letters.\n            # This works for every encoding which is a superset of ascii like\n            # utf-8 and latin-1. Non ascii chars are simply ignored.\n            line = byteline.decode('ascii', 'ignore')\n            for match in self.email_regex.finditer(line):\n                email = match.group(0)\n                if self.is_valid_email(email):\n                    emails.append(email)\n        return emails\n\n    def is_valid_email(self, email):\n        try:\n            self.email_validator(email)\n            return True\n        except ValidationError:\n            return False\n", "path": "meinberlin/apps/users/fields.py"}], "after_files": [{"content": "import re\n\nfrom django import forms\nfrom django.core.exceptions import ValidationError\nfrom django.core.validators import EmailValidator\nfrom django.forms import widgets\nfrom django.utils.translation import ugettext_lazy as _\n\n\nclass CommaSeparatedEmailField(forms.Field):\n    email_validator = EmailValidator(\n        message=_('Please enter correct email addresses, separated by '\n                  'commas.')\n    )\n\n    widget = widgets.TextInput(attrs={\n        'placeholder': 'maria@example.com, peter@example.com,\u2026'\n    })\n\n    def to_python(self, value):\n        if not value:\n            return []\n\n        emails = []\n        for email in value.split(','):\n            email = email.strip()\n            self.email_validator(email)\n            emails.append(email)\n\n        return emails\n\n\nclass EmailFileField(forms.FileField):\n    \"\"\"Extract emails from uploaded text files.\"\"\"\n\n    widget = widgets.FileInput\n    # Find possible email strings. Emails may be quoted and separated by\n    # whitespaces, commas, semicolons or < and >.\n    email_regex = re.compile(r'[^\\s;,\"\\'<]+@[^\\s;,\"\\'>]+\\.[a-z]{2,}')\n    email_validator = EmailValidator()\n\n    def clean(self, data, initial=None):\n        file = super().clean(data, initial)\n        return self._extract_emails(file)\n\n    def _extract_emails(self, file):\n        if not file:\n            return []\n\n        emails = []\n        for byteline in file:\n            # As it is difficult to guess the correct encoding of a file,\n            # email addresses are restricted to contain only ascii letters.\n            # This works for every encoding which is a superset of ascii like\n            # utf-8 and latin-1. Non ascii chars are simply ignored.\n            line = byteline.decode('ascii', 'ignore')\n            for match in self.email_regex.finditer(line):\n                email = match.group(0)\n                if self.is_valid_email(email):\n                    emails.append(email)\n        return emails\n\n    def is_valid_email(self, email):\n        try:\n            self.email_validator(email)\n            return True\n        except ValidationError:\n            return False\n", "path": "meinberlin/apps/users/fields.py"}]}