Avoid the error when computing top-level indentation.

* lisp/progmodes/python.el (python-indent-calculate-indentation):
Do not apply max to an empty list

lisp/ChangeLog

@@ -1,3 +1,8 @@
+2015-02-04  Sam Steingold  <sds@gnu.org>
+
+	* progmodes/python.el (python-indent-calculate-indentation): Avoid
+	the error when computing top-level indentation.
+
 2015-02-04  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* emacs-lisp/cl-generic.el (cl--generic-member-method): Fix paren typo.

lisp/progmodes/python.el

@@ -1068,7 +1068,9 @@ minimum."
          (levels (python-indent--calculate-levels indentation)))
     (if previous
         (python-indent--previous-level levels (current-indentation))
-      (apply #'max levels))))
+      (if levels
+          (apply #'max levels)
+        0))))
 
 (defun python-indent-line (&optional previous)
   "Internal implementation of `python-indent-line-function'.