Simplify logic

Author: StanFromIreland

Lib/gettext.py

@@ -359,21 +359,18 @@ def _parse(self, fp):
         self.plural = lambda n: int(n != 1) # germanic plural by default
         buf = fp.read()
         buflen = len(buf)
-        # Are we big endian or little endian?
-        if buflen < 4:
+        if buflen < 20:
             raise OSError(0, 'File is corrupt', filename)
+        # Are we big endian or litle endian?
         magic = unpack('<I', buf[:4])[0]
         if magic == self.LE_MAGIC:
+            version, msgcount, masteridx, transidx = unpack('<4I', buf[4:20])
             ii = '<II'
-            hdr = '<4I'
         elif magic == self.BE_MAGIC:
+            version, msgcount, masteridx, transidx = unpack('>4I', buf[4:20])
             ii = '>II'
-            hdr = '>4I'
         else:
             raise OSError(0, 'Bad magic number', filename)
-        if buflen < 20:
-            raise OSError(0, 'File is corrupt', filename)
-        version, msgcount, masteridx, transidx = unpack(hdr, buf[4:20])
 
         major_version, minor_version = self._get_versions(version)
 

Lib/test/test_gettext.py

@@ -40,7 +40,7 @@
 '''
 
 # .mo file with an invalid magic number
-GNU_MO_DATA_BAD_MAGIC_NUMBER = base64.b64encode(b'ABCD')
+GNU_MO_DATA_BAD_MAGIC_NUMBER = base64.b64encode(b'ABCD' + bytes(16))
 
 # This data contains an invalid major version number (5)
 # An unexpected major version number should be treated as an error when