Author: Alex Rousskov <rousskov@measurement-factory.com>

Bug 2651: crash handling NULL write callback

Check whether the old-style (function-based) callback has the
function address to call. A writer may leave no "callback number".

diff --git a/src/CommCalls.h b/src/CommCalls.h
index c5b39411a18d31bf10f61e5160e09ccb9c7d3167..5012e836b2ce721602adc52c79d7e76b829b417e 100644 (file)
--- a/src/CommCalls.h
+++ b/src/CommCalls.h
@@ -311,6 +311,9 @@ CommCbFunPtrCallT<Dialer>::canFire()
     if (!dialer.params.syncWithComm())
         return cancel("out of sync w/comm");
 
+    if (!dialer.handler)
+        return cancel("no callback requested");
+
     return true;
 }