6 files changed, 44 insertions, 6 deletions
diff --git a/cpp/include/Ice/Protocol.h b/cpp/include/Ice/Protocol.h
index cf14d1b85a8..8470a4549d4 100644
--- a/cpp/include/Ice/Protocol.h
+++ b/cpp/include/Ice/Protocol.h
@@ -187,6 +187,31 @@ checkSupportedEncoding(const Ice::EncodingVersion& v)
     }
 }
 
+//
+// Either return the given encoding if not compatible, or the greatest
+// supported encoding otherwise.
+//
+inline const Ice::EncodingVersion&
+checkForCompatibleEncoding(const Ice::EncodingVersion& v)
+{
+    if(v.major != Ice::currentEncoding.major)
+    {
+        return v; // Unsupported encoding, return as is.
+    }
+    else if(v.minor < Ice::currentEncoding.minor)
+    {
+        return v; // Supported encoding.
+    }
+    else
+    {
+        //
+        // Unsupported but compatible, use the currently supported
+        // encoding, that's the best we can do.
+        //
+        return Ice::currentEncoding; 
+    }
+}
+
 }
 
 #endif
diff --git a/cpp/src/Ice/LocatorInfo.cpp b/cpp/src/Ice/LocatorInfo.cpp
index 315bfdc33c6..6e51363f5ff 100644
--- a/cpp/src/Ice/LocatorInfo.cpp
+++ b/cpp/src/Ice/LocatorInfo.cpp
@@ -324,9 +324,9 @@ IceInternal::LocatorInfo::RequestCallback::response(const LocatorInfoPtr& locato
         if(_ref->isWellKnown() && !isSupported(_ref->getEncoding(), r->getEncoding()))
         {
             //
-            // If a well-known proxy and the returned proxy encoding isn't 
-            // supported, we're done: there are no compatible endpoints
-            // we can use.
+            // If a well-known proxy and the returned proxy encoding
+            // isn't supported, we're done: there's no compatible
+            // endpoint we can use.
             //
         }
         else if(!r->isIndirect())
diff --git a/cpp/src/Ice/Outgoing.cpp b/cpp/src/Ice/Outgoing.cpp
index 4f75c9957e1..51f41bedd2b 100644
--- a/cpp/src/Ice/Outgoing.cpp
+++ b/cpp/src/Ice/Outgoing.cpp
@@ -87,7 +87,7 @@ IceInternal::Outgoing::Outgoing(RequestHandler* handler, const string& operation
     _handler(handler),
     _observer(observer),
     _state(StateUnsent),
-    _encoding(handler->getReference()->getEncoding()),
+    _encoding(checkForCompatibleEncoding(handler->getReference()->getEncoding())),
     _is(handler->getReference()->getInstance().get(), Ice::currentProtocolEncoding),
     _os(handler->getReference()->getInstance().get(), Ice::currentProtocolEncoding),
     _sent(false)
diff --git a/cpp/src/Ice/OutgoingAsync.cpp b/cpp/src/Ice/OutgoingAsync.cpp
index 5ffa11d3b41..04e9eabdc02 100644
--- a/cpp/src/Ice/OutgoingAsync.cpp
+++ b/cpp/src/Ice/OutgoingAsync.cpp
@@ -426,7 +426,7 @@ IceInternal::OutgoingAsync::OutgoingAsync(const ObjectPrx& prx,
                                           const Ice::LocalObjectPtr& cookie) :
     AsyncResult(prx->ice_getCommunicator(), prx->__reference()->getInstance(), operation, delegate, cookie),
     _proxy(prx),
-    _encoding(prx->__reference()->getEncoding())
+    _encoding(checkForCompatibleEncoding(prx->__reference()->getEncoding()))
 {
 }
 
diff --git a/cpp/src/IceGrid/LocatorI.cpp b/cpp/src/IceGrid/LocatorI.cpp
index 2ebc6fbc22a..798f207dfab 100644
--- a/cpp/src/IceGrid/LocatorI.cpp
+++ b/cpp/src/IceGrid/LocatorI.cpp
@@ -187,7 +187,7 @@ public:
         //
         // Ensure the server supports the request encoding.
         //
-        if(proxy->ice_getEncodingVersion() < _encoding)
+        if(!IceInternal::isSupported(_encoding, proxy->ice_getEncodingVersion()))
         {
             exception(id, Ice::UnsupportedEncodingException(__FILE__, 
                                                             __LINE__, 
diff --git a/cpp/test/Ice/proxy/AllTests.cpp b/cpp/test/Ice/proxy/AllTests.cpp
index 65a817c5ba0..8715475f4a4 100644
--- a/cpp/test/Ice/proxy/AllTests.cpp
+++ b/cpp/test/Ice/proxy/AllTests.cpp
@@ -697,6 +697,19 @@ allTests(const Ice::CommunicatorPtr& communicator)
     cl10->ice_encodingVersion(Ice::Encoding_1_0)->ice_ping();
     cl->ice_collocationOptimized(false)->ice_encodingVersion(Ice::Encoding_1_0)->ice_ping();
 
+    // 1.3 isn't supported but since a 1.3 proxy supports 1.1, the
+    // call will use the 1.1 encoding
+    string ref13 = "test -e 1.3:default -p 12010";
+    Test::MyClassPrx cl13 = Test::MyClassPrx::uncheckedCast(communicator->stringToProxy(ref13));
+    cl13->ice_ping();
+    try
+    {
+        cl13->end_ice_ping(cl13->begin_ice_ping());
+    }
+    catch(const Ice::CollocationOptimizationException&)
+    {
+    }
+    
     try
     {
         // Send request with bogus 1.2 encoding.