do string replacements in the right order

doc/introduction.tex

@@ -21,7 +21,7 @@ would like to experiment with such techniques that haven't yet found
 their way into mainstream renderers, and it also provides a solid 
 foundation for research in this domain.
 
-Other design considerations are are:
+Other design considerations are:
 
 \parheader{Performance:}
 Mitsuba provides optimized implementations of the most commonly 

include/mitsuba/core/util.h

@@ -76,6 +76,15 @@ template<class Iterator> std::string containerToString(const Iterator &start, co
 	return oss.str();
 }
 
+/// Simple functor for sorting string parameters by length and content
+struct SimpleStringOrdering {
+	bool operator()(const std::string &a, const std::string &b) const {
+		if (a.length() == b.length())
+			return a < b;
+		return a.length() < b.length();
+	}
+};
+
 //! @}
 // -----------------------------------------------------------------------
 

include/mitsuba/render/scenehandler.h

@@ -60,7 +60,7 @@ private:
 class MTS_EXPORT_RENDER SceneHandler : public HandlerBase {
 public:
 	typedef std::map<std::string, ConfigurableObject *> NamedObjectMap;
-	typedef std::map<std::string, std::string> ParameterMap;
+	typedef std::map<std::string, std::string, SimpleStringOrdering> ParameterMap;
 
 	SceneHandler(const SAXParser *parser, const ParameterMap &params,
 			NamedObjectMap *objects = NULL, bool isIncludedFile = false);

include/mitsuba/render/util.h

@@ -41,7 +41,7 @@ public:
 
 	MTS_DECLARE_CLASS()
 protected:
-	typedef std::map<std::string, std::string> ParameterMap;
+	typedef std::map<std::string, std::string, SimpleStringOrdering> ParameterMap;
 
 	/// Virtual destructor
 	virtual ~Utility() { }

src/librender/scenehandler.cpp

@@ -105,11 +105,10 @@ void SceneHandler::startElement(const XMLCh* const xmlName,
 	ParseContext context((name == "scene") ? NULL : &m_context.top());
 
 	/* Convert attributes to ISO-8859-1 */
-	for (unsigned int i=0; i<xmlAttributes.getLength(); i++) {
+	for (size_t i=0; i<xmlAttributes.getLength(); i++) {
 		std::string attrValue = transcode(xmlAttributes.getValue(i));
 		if (attrValue.length() > 0 && attrValue.find('$') != attrValue.npos) {
-			for (std::map<std::string, std::string>::const_iterator it = m_params.begin();
-				it != m_params.end(); ++it) {
+			for (ParameterMap::const_reverse_iterator it = m_params.rbegin(); it != m_params.rend(); ++it) {
 				std::string::size_type pos = 0;
 				std::string searchString = "$" + it->first;
 				while ((pos = attrValue.find(searchString, pos)) != std::string::npos) {

src/mitsuba/mitsuba.cpp

@@ -127,7 +127,7 @@ int mts_main(int argc, char **argv) {
 		ELogLevel logLevel = EInfo;
 		ref<FileResolver> fileResolver = Thread::getThread()->getFileResolver();
 		bool testCaseMode = false, treatWarningsAsErrors = false;
-		std::map<std::string, std::string> parameters;
+		std::map<std::string, std::string, SimpleStringOrdering> parameters;
 		int blockSize = 32;
 		int flushTimer = -1;