Whitespace normalization.
diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index 3e334be..6a92a10 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -1249,7 +1249,7 @@
             if self.posix:
                 prefix = tarinfo.name[:LENGTH_PREFIX + 1]
                 while prefix and prefix[-1] != "/":
-                        prefix = prefix[:-1]
+                    prefix = prefix[:-1]
 
                 name = tarinfo.name[len(prefix):]
                 prefix = prefix[:-1]