prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  If id, schema or last_modified are marked as required, record can't be validated
  Because we pop those fields before validating them with the collection schema.
  
  We can either:
  * prevent those fields to be mentioned as `required` when defining the collection schema
  * or not pop them if they are present in the schema before validating
  If id, schema or last_modified are marked as required, record can't be validated
  Because we pop those fields before validating them with the collection schema.
  
  We can either:
  * prevent those fields to be mentioned as `required` when defining the collection schema
  * or not pop them if they are present in the schema before validating
  
  </issue>
  <code>
  [start of kinto/views/records.py]
  1 import copy
  2 
  3 import jsonschema
  4 from kinto.core import resource, utils
  5 from kinto.core.errors import raise_invalid
  6 from jsonschema import exceptions as jsonschema_exceptions
  7 from pyramid.security import Authenticated
  8 from pyramid.settings import asbool
  9 
  10 from kinto.views import object_exists_or_404
  11 
  12 
  13 _parent_path = '/buckets/{{bucket_id}}/collections/{{collection_id}}'
  14 
  15 
  16 @resource.register(name='record',
  17                    collection_path=_parent_path + '/records',
  18                    record_path=_parent_path + '/records/{{id}}')
  19 class Record(resource.ShareableResource):
  20 
  21     schema_field = 'schema'
  22 
  23     def __init__(self, request, **kwargs):
  24         # Before all, first check that the parent collection exists.
  25         # Check if already fetched before (in batch).
  26         collections = request.bound_data.setdefault('collections', {})
  27         collection_uri = self.get_parent_id(request)
  28         if collection_uri not in collections:
  29             # Unknown yet, fetch from storage.
  30             collection_parent_id = utils.instance_uri(request, 'bucket',
  31                                                       id=self.bucket_id)
  32             collection = object_exists_or_404(request,
  33                                               collection_id='collection',
  34                                               parent_id=collection_parent_id,
  35                                               object_id=self.collection_id)
  36             collections[collection_uri] = collection
  37 
  38         super().__init__(request, **kwargs)
  39         self._collection = collections[collection_uri]
  40 
  41     def get_parent_id(self, request):
  42         self.bucket_id = request.matchdict['bucket_id']
  43         self.collection_id = request.matchdict['collection_id']
  44         return utils.instance_uri(request, 'collection',
  45                                   bucket_id=self.bucket_id,
  46                                   id=self.collection_id)
  47 
  48     def process_record(self, new, old=None):
  49         """Validate records against collection schema, if any."""
  50         new = super().process_record(new, old)
  51 
  52         schema = self._collection.get('schema')
  53         settings = self.request.registry.settings
  54         schema_validation = 'experimental_collection_schema_validation'
  55         if not schema or not asbool(settings.get(schema_validation)):
  56             return new
  57 
  58         collection_timestamp = self._collection[self.model.modified_field]
  59 
  60         try:
  61             stripped = copy.deepcopy(new)
  62             stripped.pop(self.model.id_field, None)
  63             stripped.pop(self.model.modified_field, None)
  64             stripped.pop(self.model.permissions_field, None)
  65             stripped.pop(self.schema_field, None)
  66             jsonschema.validate(stripped, schema)
  67         except jsonschema_exceptions.ValidationError as e:
  68             if e.validator_value:
  69                 field = e.validator_value[-1]
  70             else:
  71                 field = e.schema_path[-1]
  72             raise_invalid(self.request, name=field, description=e.message)
  73 
  74         new[self.schema_field] = collection_timestamp
  75         return new
  76 
  77     def collection_get(self):
  78         result = super().collection_get()
  79         self._handle_cache_expires(self.request.response)
  80         return result
  81 
  82     def get(self):
  83         result = super().get()
  84         self._handle_cache_expires(self.request.response)
  85         return result
  86 
  87     def _handle_cache_expires(self, response):
  88         """If the parent collection defines a ``cache_expires`` attribute,
  89         then cache-control response headers are sent.
  90 
  91         .. note::
  92 
  93             Those headers are also sent if the
  94             ``kinto.record_cache_expires_seconds`` setting is defined.
  95         """
  96         is_anonymous = Authenticated not in self.request.effective_principals
  97         if not is_anonymous:
  98             return
  99 
  100         cache_expires = self._collection.get('cache_expires')
  101         if cache_expires is None:
  102             by_bucket = '{}_record_cache_expires_seconds'.format(self.bucket_id)
  103             by_collection = '{}_{}_record_cache_expires_seconds'.format(
  104                 self.bucket_id, self.collection_id)
  105             settings = self.request.registry.settings
  106             cache_expires = settings.get(by_collection,
  107                                          settings.get(by_bucket))
  108 
  109         if cache_expires is not None:
  110             response.cache_expires(seconds=int(cache_expires))
  111
  [end of kinto/views/records.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/kinto/views/records.py b/kinto/views/records.py
  --- a/kinto/views/records.py
  +++ b/kinto/views/records.py
  @@ -1,5 +1,3 @@
  -import copy
  -
   import jsonschema
   from kinto.core import resource, utils
   from kinto.core.errors import raise_invalid
  @@ -55,15 +53,21 @@
           if not schema or not asbool(settings.get(schema_validation)):
               return new
   
  -        collection_timestamp = self._collection[self.model.modified_field]
  -
  +        # Remove internal and auto-assigned fields from schema and record.
  +        internal_fields = (self.model.id_field,
  +                           self.model.modified_field,
  +                           self.schema_field,
  +                           self.model.permissions_field)
  +        required_fields = [f for f in schema.get('required', []) if f not in internal_fields]
  +        if required_fields:
  +            schema = {**schema, 'required': required_fields}
  +        else:
  +            schema = {f: v for f, v in new.items() if f != 'required'}
  +        data = {f: v for f, v in new.items() if f not in internal_fields}
  +
  +        # Validate or fail with 400.
           try:
  -            stripped = copy.deepcopy(new)
  -            stripped.pop(self.model.id_field, None)
  -            stripped.pop(self.model.modified_field, None)
  -            stripped.pop(self.model.permissions_field, None)
  -            stripped.pop(self.schema_field, None)
  -            jsonschema.validate(stripped, schema)
  +            jsonschema.validate(data, schema)
           except jsonschema_exceptions.ValidationError as e:
               if e.validator_value:
                   field = e.validator_value[-1]
  @@ -71,7 +75,10 @@
                   field = e.schema_path[-1]
               raise_invalid(self.request, name=field, description=e.message)
   
  +        # Assign the schema version (collection object timestamp) to the record.
  +        collection_timestamp = self._collection[self.model.modified_field]
           new[self.schema_field] = collection_timestamp
  +
           return new
   
       def collection_get(self):
  
verification_info: {"golden_diff": "diff --git a/kinto/views/records.py b/kinto/views/records.py\n--- a/kinto/views/records.py\n+++ b/kinto/views/records.py\n@@ -1,5 +1,3 @@\n-import copy\n-\n import jsonschema\n from kinto.core import resource, utils\n from kinto.core.errors import raise_invalid\n@@ -55,15 +53,21 @@\n         if not schema or not asbool(settings.get(schema_validation)):\n             return new\n \n-        collection_timestamp = self._collection[self.model.modified_field]\n-\n+        # Remove internal and auto-assigned fields from schema and record.\n+        internal_fields = (self.model.id_field,\n+                           self.model.modified_field,\n+                           self.schema_field,\n+                           self.model.permissions_field)\n+        required_fields = [f for f in schema.get('required', []) if f not in internal_fields]\n+        if required_fields:\n+            schema = {**schema, 'required': required_fields}\n+        else:\n+            schema = {f: v for f, v in new.items() if f != 'required'}\n+        data = {f: v for f, v in new.items() if f not in internal_fields}\n+\n+        # Validate or fail with 400.\n         try:\n-            stripped = copy.deepcopy(new)\n-            stripped.pop(self.model.id_field, None)\n-            stripped.pop(self.model.modified_field, None)\n-            stripped.pop(self.model.permissions_field, None)\n-            stripped.pop(self.schema_field, None)\n-            jsonschema.validate(stripped, schema)\n+            jsonschema.validate(data, schema)\n         except jsonschema_exceptions.ValidationError as e:\n             if e.validator_value:\n                 field = e.validator_value[-1]\n@@ -71,7 +75,10 @@\n                 field = e.schema_path[-1]\n             raise_invalid(self.request, name=field, description=e.message)\n \n+        # Assign the schema version (collection object timestamp) to the record.\n+        collection_timestamp = self._collection[self.model.modified_field]\n         new[self.schema_field] = collection_timestamp\n+\n         return new\n \n     def collection_get(self):\n", "issue": "If id, schema or last_modified are marked as required, record can't be validated\nBecause we pop those fields before validating them with the collection schema.\r\n\r\nWe can either:\r\n* prevent those fields to be mentioned as `required` when defining the collection schema\r\n* or not pop them if they are present in the schema before validating\nIf id, schema or last_modified are marked as required, record can't be validated\nBecause we pop those fields before validating them with the collection schema.\r\n\r\nWe can either:\r\n* prevent those fields to be mentioned as `required` when defining the collection schema\r\n* or not pop them if they are present in the schema before validating\n", "before_files": [{"content": "import copy\n\nimport jsonschema\nfrom kinto.core import resource, utils\nfrom kinto.core.errors import raise_invalid\nfrom jsonschema import exceptions as jsonschema_exceptions\nfrom pyramid.security import Authenticated\nfrom pyramid.settings import asbool\n\nfrom kinto.views import object_exists_or_404\n\n\n_parent_path = '/buckets/{{bucket_id}}/collections/{{collection_id}}'\n\n\n@resource.register(name='record',\n                   collection_path=_parent_path + '/records',\n                   record_path=_parent_path + '/records/{{id}}')\nclass Record(resource.ShareableResource):\n\n    schema_field = 'schema'\n\n    def __init__(self, request, **kwargs):\n        # Before all, first check that the parent collection exists.\n        # Check if already fetched before (in batch).\n        collections = request.bound_data.setdefault('collections', {})\n        collection_uri = self.get_parent_id(request)\n        if collection_uri not in collections:\n            # Unknown yet, fetch from storage.\n            collection_parent_id = utils.instance_uri(request, 'bucket',\n                                                      id=self.bucket_id)\n            collection = object_exists_or_404(request,\n                                              collection_id='collection',\n                                              parent_id=collection_parent_id,\n                                              object_id=self.collection_id)\n            collections[collection_uri] = collection\n\n        super().__init__(request, **kwargs)\n        self._collection = collections[collection_uri]\n\n    def get_parent_id(self, request):\n        self.bucket_id = request.matchdict['bucket_id']\n        self.collection_id = request.matchdict['collection_id']\n        return utils.instance_uri(request, 'collection',\n                                  bucket_id=self.bucket_id,\n                                  id=self.collection_id)\n\n    def process_record(self, new, old=None):\n        \"\"\"Validate records against collection schema, if any.\"\"\"\n        new = super().process_record(new, old)\n\n        schema = self._collection.get('schema')\n        settings = self.request.registry.settings\n        schema_validation = 'experimental_collection_schema_validation'\n        if not schema or not asbool(settings.get(schema_validation)):\n            return new\n\n        collection_timestamp = self._collection[self.model.modified_field]\n\n        try:\n            stripped = copy.deepcopy(new)\n            stripped.pop(self.model.id_field, None)\n            stripped.pop(self.model.modified_field, None)\n            stripped.pop(self.model.permissions_field, None)\n            stripped.pop(self.schema_field, None)\n            jsonschema.validate(stripped, schema)\n        except jsonschema_exceptions.ValidationError as e:\n            if e.validator_value:\n                field = e.validator_value[-1]\n            else:\n                field = e.schema_path[-1]\n            raise_invalid(self.request, name=field, description=e.message)\n\n        new[self.schema_field] = collection_timestamp\n        return new\n\n    def collection_get(self):\n        result = super().collection_get()\n        self._handle_cache_expires(self.request.response)\n        return result\n\n    def get(self):\n        result = super().get()\n        self._handle_cache_expires(self.request.response)\n        return result\n\n    def _handle_cache_expires(self, response):\n        \"\"\"If the parent collection defines a ``cache_expires`` attribute,\n        then cache-control response headers are sent.\n\n        .. note::\n\n            Those headers are also sent if the\n            ``kinto.record_cache_expires_seconds`` setting is defined.\n        \"\"\"\n        is_anonymous = Authenticated not in self.request.effective_principals\n        if not is_anonymous:\n            return\n\n        cache_expires = self._collection.get('cache_expires')\n        if cache_expires is None:\n            by_bucket = '{}_record_cache_expires_seconds'.format(self.bucket_id)\n            by_collection = '{}_{}_record_cache_expires_seconds'.format(\n                self.bucket_id, self.collection_id)\n            settings = self.request.registry.settings\n            cache_expires = settings.get(by_collection,\n                                         settings.get(by_bucket))\n\n        if cache_expires is not None:\n            response.cache_expires(seconds=int(cache_expires))\n", "path": "kinto/views/records.py"}]}