updated merge to handle base image saving

disk.py

@@ -3,7 +3,7 @@ import os
 import subprocess
 import re
 import logging
-from shutil import move, copyfileobj
+from shutil import move, copy, copyfileobj
 from zipfile import ZipFile, is_zipfile
 from zlib import decompressobj, MAX_WBITS
 from bz2 import BZ2Decompressor
@@ -226,10 +226,7 @@ class Disk(object):
         # Check if file already exists
         if os.path.isfile(new_disk.get_path()):
             raise Exception('File already exists: %s' % self.get_path())
-        # Check if base file exist
-        if not os.path.isfile(self.get_base()):
-            raise Exception('Original image does not exists: %s'
-                            % self.get_base())
+        if self.base_name:
             cmdline = ['qemu-img',
                        'convert',
                        self.get_path(),
@@ -237,6 +234,8 @@ class Disk(object):
                        new_disk.get_path()]
             # Call subprocess
             subprocess.check_output(cmdline)
+        else:
+            copy(self.get_path(), new_disk.get_path())
 
     def delete(self):
         ''' Delete file