From adce9e6220616ee030041da7ee6c12f78a133132 Mon Sep 17 00:00:00 2001
From: Emmanuel Leblond <emmanuel.leblond@gmail.com>
Date: Fri, 19 Feb 2016 01:58:15 +0100
Subject: [PATCH] Raise OperationError in drop_collection if no collection is
 set

---
 docs/changelog.rst      |  1 +
 mongoengine/document.py | 12 +++++++++++-
 tests/fields/fields.py  | 10 ++++++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index 3794e9e3..069872ec 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -7,6 +7,7 @@ Changes in 0.10.7 - DEV
 - Fixed not being able to specify `use_db_field=False` on `ListField(EmbeddedDocumentField)` instances
 - Fixed cascade delete mixing among collections #1224
 - Add `signal_kwargs` argument to `Document.save`, `Document.delete` and `BaseQuerySet.insert` to be passed to signals calls #1206
+- Raise `OperationError` when trying to do a `drop_collection` on document with no collection set.
 
 Changes in 0.10.6
 =================
diff --git a/mongoengine/document.py b/mongoengine/document.py
index 8211d95e..52353523 100644
--- a/mongoengine/document.py
+++ b/mongoengine/document.py
@@ -679,10 +679,20 @@ class Document(BaseDocument):
     def drop_collection(cls):
         """Drops the entire collection associated with this
         :class:`~mongoengine.Document` type from the database.
+
+        Raises :class:`OperationError` if the document has no collection set
+        (i.g. if it is `abstract`)
+
+        .. versionchanged:: 0.10.7
+            :class:`OperationError` exception raised if no collection available
         """
+        col_name = cls._get_collection_name()
+        if not col_name:
+            raise OperationError('Document %s has no collection defined '
+                                 '(is it abstract ?)' % cls)
         cls._collection = None
         db = cls._get_db()
-        db.drop_collection(cls._get_collection_name())
+        db.drop_collection(col_name)
 
     @classmethod
     def create_index(cls, keys, background=False, **kwargs):
diff --git a/tests/fields/fields.py b/tests/fields/fields.py
index bf2b5dd5..eb2f46c7 100644
--- a/tests/fields/fields.py
+++ b/tests/fields/fields.py
@@ -2285,6 +2285,16 @@ class FieldTest(unittest.TestCase):
         Member.drop_collection()
         BlogPost.drop_collection()
 
+    def test_drop_abstract_document(self):
+        """Ensure that an abstract document cannot be dropped given it
+        has no underlying collection.
+        """
+        class AbstractDoc(Document):
+            name = StringField()
+            meta = {"abstract": True}
+
+        self.assertRaises(OperationError, AbstractDoc.drop_collection)
+
     def test_reference_class_with_abstract_parent(self):
         """Ensure that a class with an abstract parent can be referenced.
         """