Merge pull request #93 from matthew-brett/csa-itemlen0-fix

BF+TST - Allow 0 len items in CSA hdr if VM != 0

Author: matthew-brett

nibabel/nicom/csareader.py

@@ -137,13 +137,12 @@ def read(csa_str):
                 continue
             item = nt_str(up_str.read(item_len))
             if converter:
-                if vm == 0:
-                    # we may have fewer real items than are given in
-                    # n_items, but we don't know how many - assume that
-                    # we've reached the end when we hit an empty item
-                    if item_len == 0:
-                        n_values = item_no
-                        continue
+                # we may have fewer real items than are given in
+                # n_items, but we don't know how many - assume that
+                # we've reached the end when we hit an empty item
+                if item_len == 0:
+                    n_values = item_no
+                    continue
                 item = converter(item)
             items.append(item)
             # go to 4 byte boundary

nibabel/nicom/tests/data/csa2_zero_len.bin.gz

@@ -1,6 +1,7 @@
 """ Testing Siemens CSA header reader
 """
 from os.path import join as pjoin
+import gzip
 
 import numpy as np
 
@@ -17,6 +18,7 @@
 
 CSA2_B0 = open(pjoin(IO_DATA_PATH, 'csa2_b0.bin'), 'rb').read()
 CSA2_B1000 = open(pjoin(IO_DATA_PATH, 'csa2_b1000.bin'), 'rb').read()
+CSA2_0len = gzip.open(pjoin(IO_DATA_PATH, 'csa2_zero_len.bin.gz'), 'rb').read()
 
 
 @dicom_test
@@ -44,6 +46,15 @@ def test_csas0():
     assert_equal(b_value['items'], [1000])
 
 
+def test_csa_len0():
+    # We did get a failure for item with item_len of 0 - gh issue #92
+    csa_info = csa.read(CSA2_0len)
+    assert_equal(csa_info['type'], 2)
+    assert_equal(csa_info['n_tags'], 44)
+    tags = csa_info['tags']
+    assert_equal(len(tags), 44)
+
+
 def test_csa_params():
     for csa_str in (CSA2_B0, CSA2_B1000):
         csa_info = csa.read(csa_str)