FileUpload objects now eval false if filename is empty.

Upload buttons on DTML, Py Scripts, Files, Images and PTs raise an error
if the file is not specified instead of clearing the source (Bug #144)

PythonScript.py

@@ -17,7 +17,7 @@
 Python code.
 """
 
-__version__='$Revision: 1.41 $'[11:-2]
+__version__='$Revision: 1.42 $'[11:-2]
 
 import sys, os, traceback, re, marshal
 from Globals import DTMLFile, MessageDialog, package_home
@@ -153,7 +153,11 @@ def ZPythonScriptHTML_upload(self, REQUEST, file=''):
         """Replace the body of the script with the text in file."""
         if self.wl_isLocked():
             raise ResourceLockedError, "The script is locked via WebDAV."
-        if type(file) is not type(''): file = file.read()
+
+        if type(file) is not type(''): 
+            if not file: raise ValueError, 'File not specified'
+            file = file.read()
+
         self.write(file)
         message = 'Saved changes.'
         return self.ZPythonScriptHTML_editForm(self, REQUEST,