Detect if user specifies an unknown property name

olla/src/Platform.cpp

@@ -88,7 +88,12 @@ const string& Platform::getPropertyDefaultValue(const string& property) const {
 }
 
 void Platform::setPropertyDefaultValue(const string& property, const string& value) {
-    defaultProperties[property] = value;
+    for (int i = 0; i < (int) platformProperties.size(); i++)
+        if (platformProperties[i] == property) {
+            defaultProperties[property] = value;
+            return;
+        }
+    throw OpenMMException("setPropertyDefaultValue: Illegal property name");
 }
 
 void Platform::contextCreated(ContextImpl& context, const map<string, string>& properties) const {

openmmapi/src/ContextImpl.cpp

@@ -75,6 +75,20 @@ ContextImpl::ContextImpl(Context& owner, const System& system, Integrator& integ
             throw OpenMMException("A constraint cannot involve a massless particle");
     }
     
+    // Validate the list of properties.
+
+    const vector<string>& platformProperties = platform->getPropertyNames();
+    for (map<string, string>::const_iterator iter = properties.begin(); iter != properties.end(); ++iter) {
+        bool valid = false;
+        for (int i = 0; i < (int) platformProperties.size(); i++)
+            if (platformProperties[i] == iter->first) {
+                valid = true;
+                break;
+            }
+        if (!valid)
+            throw OpenMMException("Illegal property name: "+iter->first);
+    }
+    
     // Find the list of kernels required.
     
     vector<string> kernelNames;