Merge branch 'lupien-fix_lock_excl'

pyvisa · May 19, 2015 · 8fc41ff · 8fc41ff
2 parents b5a44aa + e4ab706
commit 8fc41ff
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/pyvisa/ctwrapper/functions.py b/pyvisa/ctwrapper/functions.py
@@ -796,7 +796,10 @@ def lock(library, session, lock_type, timeout, requested_key=None):
     else:
         access_key = create_string_buffer(256)
     ret = library.viLock(session, lock_type, timeout, requested_key, access_key)
-    return access_key.value, ret
+    if access_key is None:
+        return None, ret
+    else:
+        return access_key.value, ret
 
 
 def map_address(library, session, map_space, map_base, map_size,