made lib more robust if server sends duplicate connect channel response

src/ca/cac.cpp

@@ -1046,9 +1046,16 @@ bool cac::createChannelRespAction (
         else {
             sidTmp = pChan->getSID (guard);
         }
-        iiu.connectNotify ( guard, *pChan );
-        pChan->connect ( hdr.m_dataType, hdr.m_count, sidTmp, 
-            mgr.cbGuard, guard );
+        bool wasExpected = iiu.connectNotify ( guard, *pChan );
+        if ( wasExpected ) {
+            pChan->connect ( hdr.m_dataType, hdr.m_count, sidTmp, 
+                mgr.cbGuard, guard );
+        }
+        else {
+            errlogPrintf ( 
+                "CA Client Library: Ignored duplicate create channel "
+                "response from CA server?\n" );
+        }
     }
     else if ( iiu.ca_v44_ok ( guard ) ) {
         // this indicates a claim response for a resource that does

src/ca/tcpiiu.cpp

@@ -1916,24 +1916,28 @@ void tcpiiu::nameResolutionMsgEndNotify ()
     }
 }
 
-void tcpiiu::connectNotify ( 
+bool tcpiiu :: connectNotify ( 
     epicsGuard < epicsMutex > & guard, nciu & chan )
 {
     guard.assertIdenticalMutex ( this->mutex );
+    bool wasExpected = false;
     // this improves robustness in the face of a server sending
     // protocol that does not match its declared protocol revision
     if ( chan.channelNode::listMember == channelNode::cs_createRespPend ) {
         this->createRespPend.remove ( chan );
         this->subscripReqPend.add ( chan );
         chan.channelNode::listMember = channelNode::cs_subscripReqPend;
+        wasExpected = true;
     }
     else if ( chan.channelNode::listMember == channelNode::cs_v42ConnCallbackPend ) {
         this->v42ConnCallbackPend.remove ( chan );
         this->subscripReqPend.add ( chan );
         chan.channelNode::listMember = channelNode::cs_subscripReqPend;
+        wasExpected = true;
     }
     // the TCP send thread is awakened by its receive thread whenever the receive thread
     // is about to block if this->subscripReqPend has items in it
+    return wasExpected;
 }
 
 void tcpiiu::uninstallChan ( 

src/ca/virtualCircuit.h

@@ -173,7 +173,7 @@ public:
         unsigned sidIn, ca_uint16_t typeIn, arrayElementCount countIn );
     void uninstallChan ( 
         epicsGuard < epicsMutex > & guard, nciu & chan );
-    void connectNotify ( 
+    bool connectNotify ( 
         epicsGuard < epicsMutex > &, nciu & chan );
     void nameResolutionMsgEndNotify ();