Fix alphanumeric address decoding (issue #36)

Author: faucamp

gsmmodem/pdu.py

@@ -4,10 +4,9 @@
 
 from __future__ import unicode_literals
 
-import sys, codecs
+import sys, codecs, math
 from datetime import datetime, timedelta, tzinfo
 from copy import copy
-import codecs
 from .exceptions import EncodingError
 
 # For Python 3 support
@@ -549,7 +548,7 @@ def _decodeAddressField(byteIter, smscField=False, log=False):
         ton = (toa & 0x70) # bits 6,5,4 of type-of-address == type-of-number
         if ton == 0x50: 
             # Alphanumberic number            
-            addressLen /= 2
+            addressLen = int(math.ceil(addressLen / 2.0))
             septets = unpackSeptets(byteIter, addressLen)
             addressValue = decodeGsm7(septets)
             return (addressValue, (addressLen + 2))

test/test_pdu.py

@@ -422,7 +422,13 @@ def test_decode(self):
                    'number': '+b08427829207025', # <- broken number (invalid PDU data; the reference number is more than a single byte (or they added something))
                    'reference': 28,
                    'time': datetime(2013, 7, 26, 14, 29, 27, tzinfo=SimpleOffsetTzInfo(2)),
-                   'discharge': datetime(2013, 7, 26, 14, 29, 31, tzinfo=SimpleOffsetTzInfo(2))})
+                   'discharge': datetime(2013, 7, 26, 14, 29, 31, tzinfo=SimpleOffsetTzInfo(2))}),
+                 (b'07919762020033F1400DD0CDF2396C7EBB010008415072411084618C0500035602010053004D005300200063006F00640065003A00200034003800350036002C00200063006F006E006600690072006D006100740069006F006E0020006F00660020006100730073006F00630069006100740069006F006E0020006200650074007700650065006E0020006100630063006F0075006E007400200061006E00640020004D00650067',
+                  {'type': 'SMS-DELIVER',
+                   'smsc': '+79262000331',
+                   'number': 'Megafon',
+                   'text': 'SMS code: 4856, confirmation of association between account and Meg',
+                   'time': datetime(2014, 5, 27, 14, 1, 48, tzinfo=SimpleOffsetTzInfo(4))})
                  )
 
         for pdu, expected in tests: