Fixed an undo bug that affects file storages that support blobs in

special cases involving undo of undo of undo of object additions.

src/ZODB/FileStorage/FileStorage.py

@@ -984,7 +984,11 @@ class FileStorage(
             else:
 
                 if self.blob_dir and not p and prev:
+                    try:
                         up, userial = self._loadBackTxn(h.oid, prev)
+                    except ZODB.POSException.POSKeyError:
+                        pass # It was removed, so no need to copy data
+                    else:
                         if ZODB.blob.is_blob_record(up):
                             # We're undoing a blob modification operation.
                             # We have to copy the blob data

src/ZODB/tests/testFileStorage.py

@@ -27,18 +27,8 @@ from ZODB.tests import RevisionStorage, PersistentStorage, MTStorage
 from ZODB.tests import ReadOnlyStorage, RecoveryStorage
 from ZODB.tests.StorageTestBase import MinPO, zodb_pickle
 
-class BaseFileStorageTests(StorageTestBase.StorageTestBase):
-
-    def open(self, **kwargs):
-        self._storage = ZODB.FileStorage.FileStorage('FileStorageTests.fs',
-                                                     **kwargs)
-
-    def setUp(self):
-        StorageTestBase.StorageTestBase.setUp(self)
-        self.open(create=1)
-
 class FileStorageTests(
-    BaseFileStorageTests,
+    StorageTestBase.StorageTestBase,
     BasicStorage.BasicStorage,
     TransactionalUndoStorage.TransactionalUndoStorage,
     RevisionStorage.RevisionStorage,
@@ -55,6 +45,14 @@ class FileStorageTests(
     ReadOnlyStorage.ReadOnlyStorage
     ):
 
+    def open(self, **kwargs):
+        self._storage = ZODB.FileStorage.FileStorage('FileStorageTests.fs',
+                                                     **kwargs)
+
+    def setUp(self):
+        StorageTestBase.StorageTestBase.setUp(self)
+        self.open(create=1)
+
     def checkLongMetadata(self):
         s = "X" * 75000
         try:
@@ -287,6 +285,13 @@ class FileStorageTests(
             else:
                 self.assertNotEqual(next_oid, None)
 
+class FileStorageTestsWithBlobsEnabled(FileStorageTests):
+
+    def open(self, **kwargs):
+        if 'blob_dir' not in kwargs:
+            kwargs = kwargs.copy()
+            kwargs['blob_dir'] = 'blobs'
+        return FileStorageTests.open(self, **kwargs)
 
 class FileStorageRecoveryTest(
     StorageTestBase.StorageTestBase,
@@ -302,7 +307,6 @@ class FileStorageRecoveryTest(
         self._dst.close()
         StorageTestBase.StorageTestBase.tearDown(self)
 
-
     def new_dest(self):
         return ZODB.FileStorage.FileStorage('Dest.fs')
 
@@ -332,23 +336,6 @@ class FileStorageNoRestoreRecoveryTest(FileStorageRecoveryTest):
         pass
 
 
-class SlowFileStorageTest(BaseFileStorageTests):
-
-    def check10Kstores(self):
-        # The _get_cached_serial() method has a special case
-        # every 8000 calls.  Make sure it gets minimal coverage.
-        oids = [[self._storage.new_oid(), None] for i in range(100)]
-        for i in range(100):
-            t = transaction.Transaction()
-            self._storage.tpc_begin(t)
-            for j in range(100):
-                o = MinPO(j)
-                oid, revid = oids[j]
-                serial = self._storage.store(oid, revid, zodb_pickle(o), "", t)
-                oids[j][1] = serial
-            self._storage.tpc_vote(t)
-            self._storage.tpc_finish(t)
-
 # Raise an exception if the tids in FileStorage fs aren't
 # strictly increasing.
 def checkIncreasingTids(fs):
@@ -586,7 +573,8 @@ def test_suite():
     suite = unittest.TestSuite()
     for klass in [FileStorageTests, Corruption.FileStorageCorruptTests,
                   FileStorageRecoveryTest, FileStorageNoRestoreRecoveryTest,
-                  SlowFileStorageTest]:
+                  FileStorageTestsWithBlobsEnabled,
+                  ]:
         suite.addTest(unittest.makeSuite(klass, "check"))
     suite.addTest(doctest.DocTestSuite(
         setUp=zope.testing.setupstack.setUpDirectory,