Behavior on value types doesn't work for all combinations

import QtQuick 2.0

Rectangle {
    width: 400
    height: 400
    color.r: 0
    color.g: 1
    color.b: 0

    Behavior on color { ColorAnimation { duration: 500; } }
}

import QtQuick 2.0

Rectangle {
    width: 400
    height: 400
    color: "green"

    Behavior on color.r { ColorAnimation { duration: 500; } }
}

diff --git a/src/declarative/qml/qdeclarativecompiler.cpp b/src/declarative/qml/qdeclarativecompiler.cpp
index fb98a8c..900ffd3 100644
--- a/src/declarative/qml/qdeclarativecompiler.cpp
+++ b/src/declarative/qml/qdeclarativecompiler.cpp
@@ -1997,10 +1997,15 @@ bool QDeclarativeCompiler::buildGroupedProperty(QDeclarativeScript::Property *pr
         if (prop->type >= 0 && enginePrivate->valueTypes[prop->type]) {
 
             if (!prop->values.isEmpty()) {
-                if (prop->values.first()->location < prop->value->location) {
-                    COMPILE_EXCEPTION(prop->value, tr( "Property has already been assigned a value"));
-                } else {
-                    COMPILE_EXCEPTION(prop->values.first(), tr( "Property has already been assigned a value"));
+                //only error if we are assigning values, and not e.g. a property interceptor
+                for (Property *dotProp = prop->value->properties.first(); dotProp; dotProp = prop->value->properties.next(dotProp)) {
+                    if (!dotProp->values.isEmpty()) {
+                        if (prop->values.first()->location < prop->value->location) {
+                            COMPILE_EXCEPTION(prop->value, tr( "Property has already been assigned a value"));
+                        } else {
+                            COMPILE_EXCEPTION(prop->values.first(), tr( "Property has already been assigned a value"));
+                        }
+                    }
                 }
             }