Fix shutil.move implementation

If both the source and destination argument of shutil.move are
directories the source directory is copied under the target directory.
pyfakefs implementation copied the source directory to the target
directory.

The real shutil.move call shutil.copy('/path/to/src', '/path/to/dest')
moves /path/to/src to /path/to/dest/src but the pyfakefs implementation
moved the src directory to /path/to/dest

fake_filesystem_shutil_test.py

@@ -273,8 +273,8 @@ def testMoveDirectory(self):
         self.assertFalse(self.filesystem.Exists(dst_directory))
         self.shutil.move(src_directory, dst_directory)
         self.assertTrue(self.filesystem.Exists(dst_directory))
-        self.assertTrue(self.filesystem.Exists('%s/subfile' % dst_directory))
-        self.assertTrue(self.filesystem.Exists('%s/subdir' % dst_directory))
+        self.assertTrue(self.filesystem.Exists('%s/%s/subfile' % (dst_directory, src_directory)))
+        self.assertTrue(self.filesystem.Exists('%s/%s/subdir' % (dst_directory, src_directory)))
         self.assertFalse(self.filesystem.Exists(src_directory))
 
     @unittest.skipIf(sys.version_info < (3, 3), 'New in Python 3.3')

pyfakefs/fake_filesystem_shutil.py

@@ -285,8 +285,10 @@ def _destinsrc(src, dst):
             return dst
 
         source_is_dir = stat.S_ISDIR(self.filesystem.GetObject(src).st_mode)
-        if source_is_dir and self.filesystem.Exists(dst):
-            raise shutil.Error("Destination path '%s' already exists" % dst)
+        if source_is_dir:
+            dst = self.filesystem.JoinPaths(dst, os.path.basename(src))
+            if self.filesystem.Exists(dst):
+                raise shutil.Error("Destination path '%s' already exists" % dst)
 
         try:
             self.filesystem.RenameObject(src, dst)