Fixed problem when creating a new EdfFile (for writing)

EdfFile.py

@@ -87,7 +87,7 @@
       through GetData method call.      
 """
 __author__ =  'Alexandre Gobbo (gobbo@esrf.fr)'
-__version__=  '$Revision: 1.14 $'
+__version__=  '$Revision: 1.15 $'
 
 ################################################################################  
 import sys, string
@@ -188,12 +188,16 @@ class  EdfFile:
                 raise "EdfFile: Error opening file"
         else: self.__ownedOpen = False
 
-        self.File.seek(0, 0)
-        
         Index=0
 
         self.__splitexp = re.compile('([A-Za-z_0-9\-]+)\s*=\s*(.+?)\s*;\s*\n')
         self.__checkEdfFile = re.compile('^dim_1',re.IGNORECASE|re.MULTILINE)
+
+        self.File.seek(0, 0)
+	if self.File.read(1) == '':
+	    return 
+        self.File.seek(0, 0)
+
         startHeaderPos = self.File.tell()
         header,headersize = self.__readOneHeader()
         while 1 :