Android: Save settings in onStop

android/app/src/main/java/net/minetest/minetest/GameActivity.java

@@ -85,6 +85,17 @@ protected void onResume() {
 		makeFullScreen();
 	}
 
+	private native void saveSettings();
+
+	@Override
+	protected void onStop() {
+		super.onStop();
+		// Avoid losing setting changes in case the app is onDestroy()ed later.
+		// Saving stuff in onStop() is recommended in the Android activity
+		// lifecycle documentation.
+		saveSettings();
+	}
+
 	@Override
 	public void onBackPressed() {
 		// Ignore the back press so Minetest can handle it

src/porting_android.cpp

@@ -28,6 +28,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "config.h"
 #include "filesys.h"
 #include "log.h"
+#include "settings.h"
 
 #include <sstream>
 #include <exception>
@@ -39,6 +40,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 extern int main(int argc, char *argv[]);
 
+extern "C" JNIEXPORT void JNICALL
+Java_net_minetest_minetest_GameActivity_saveSettings(JNIEnv* env, jobject /* this */) {
+	if (!g_settings_path.empty())
+		g_settings->updateConfigFile(g_settings_path.c_str());
+}
+
 namespace porting {
 	// used here:
 	void cleanupAndroid();