PIConfig adopt for PIIOString changes

libs/main/io_devices/piconfig.cpp

@@ -334,7 +334,7 @@ bool PIConfig::open(const PIString & path, PIIODevice::DeviceMode mode) {
 bool PIConfig::open(PIString * string, PIIODevice::DeviceMode mode) {
 	_destroy();
 	own_dev = true;
-	dev     = new PIIOString(string, mode);
+	dev     = new PIIOString(string, PIIODevice::ReadOnly);
 	_setupDev();
 	parse();
 	return true;
@@ -365,10 +365,7 @@ void PIConfig::_init() {
 
 
 void PIConfig::_destroy() {
-	if (stream) {
-		delete stream;
-		stream = nullptr;
-	}
+	piDeleteSafety(stream);
 	if (own_dev && dev) delete dev;
 	dev = nullptr;
 	piForeach(PIConfig * c, inc_devs)
@@ -392,6 +389,7 @@ void PIConfig::_clearDev() {
 	}
 	if (PIString(dev->className()) == "PIIOString") {
 		((PIIOString *)dev)->clear();
+		((PIIOString *)dev)->setMode(PIIODevice::WriteOnly);
 		return;
 	}
 }
@@ -419,6 +417,7 @@ void PIConfig::_seekToBeginDev() {
 	}
 	if (PIString(dev->className()) == "PIIOString") {
 		((PIIOString *)dev)->seekToBegin();
+		((PIIOString *)dev)->setMode(PIIODevice::ReadOnly);
 		return;
 	}
 }