--- shutil-2.6.py	2010-10-02 14:58:21.973892831 +0100
+++ /usr/lib/python2.6/shutil.py	2010-10-02 15:04:31.705905708 +0100
@@ -21,13 +21,23 @@
 except NameError:
     WindowsError = None
 
-def copyfileobj(fsrc, fdst, length=16*1024):
+SPARSE_AUTO   = 0
+SPARSE_ALWAYS = 1
+SPARSE_NEVER  = 2
+
+def copyfileobj(fsrc, fdst, length=16*1024, make_sparse=False):
     """copy data from file-like object fsrc to file-like object fdst"""
     while 1:
         buf = fsrc.read(length)
         if not buf:
             break
-        fdst.write(buf)
+        if make_sparse and buf == '\0'*len(buf):
+            fdst.seek(len(buf), os.SEEK_CUR)
+        else:
+            fdst.write(buf)
+    if make_sparse:
+        # Make sure the file ends where it should, even if padded out.
+        fdst.truncate()
 
 def _samefile(src, dst):
     # Macintosh, Unix.
@@ -41,7 +51,7 @@
     return (os.path.normcase(os.path.abspath(src)) ==
             os.path.normcase(os.path.abspath(dst)))
 
-def copyfile(src, dst):
+def copyfile(src, dst, sparse_mode=SPARSE_AUTO):
     """Copy data from src to dst"""
     if _samefile(src, dst):
         raise Error, "`%s` and `%s` are the same file" % (src, dst)
@@ -51,7 +61,19 @@
     try:
         fsrc = open(src, 'rb')
         fdst = open(dst, 'wb')
-        copyfileobj(fsrc, fdst)
+        if sparse_mode == SPARSE_NEVER:
+            make_sparse = False
+        elif sparse_mode == SPARSE_ALWAYS:
+            make_sparse = True
+        else:
+            # Assume it's AUTO
+            stat = os.fstat(fsrc.fileno())
+            if hasattr(stat, 'st_blocks') and hasattr(stat, 'st_blksize'):
+                disksize = stat.st_blocks * stat.st_blksize
+                make_sparse = (disksize < stat.st_size)
+            else:
+                make_sparse = False
+        copyfileobj(fsrc, fdst, make_sparse=make_sparse)
     finally:
         if fdst:
             fdst.close()