improve save redirection

app/src/main/cpp/launcher-fix.cpp

@@ -81,32 +81,53 @@ JNIEXPORT jboolean JNICALL Java_com_geode_launcher_LauncherFix_loadLibraryFromOf
     return true;
 }
 
-FILE* (*fopen_original)(const char *pathname, const char *mode);
-FILE* fopen_hook(const char* pathname, const char* mode) {
+std::string redirect_path(const char* pathname) {
     auto data_path = DataPaths::get_instance().data_path;
     auto original_data_path = DataPaths::get_instance().original_data_path;
 
     if (!data_path.empty() && !original_data_path.empty()) {
-        auto path_str = std::string(pathname);
-        auto pos = path_str.find(original_data_path);
-        if (pos != std::string::npos) {
-            path_str.replace(pos, original_data_path.length(), data_path);
+        // call this a c string optimization
+        if (std::strncmp(pathname, original_data_path.c_str(), original_data_path.size()) == 0) {
+            auto path = data_path + (pathname + original_data_path.size());
+
+            return path;
         }
+    }
+
+    return pathname;
+}
+
+FILE* (*fopen_original)(const char *pathname, const char *mode);
+FILE* fopen_hook(const char* pathname, const char* mode) {
+    auto path_str = redirect_path(pathname);
 
     return fopen_original(path_str.c_str(), mode);
 }
 
-    return fopen_original(pathname, mode);
+int (*rename_original)(const char* old_path, const char* new_path);
+int rename_hook(const char* old_path, const char* new_path) {
+    auto old_path_str = redirect_path(old_path);
+    auto new_path_str = redirect_path(new_path);
+
+    return rename_original(old_path_str.c_str(), new_path_str.c_str());
 }
 
 [[gnu::constructor]] [[gnu::used]] void setup_hooks() {
     #ifndef DISABLE_LAUNCHER_FIX
     auto fopen_addr = dlsym(RTLD_NEXT, "fopen");
+    auto rename_addr = dlsym(RTLD_NEXT, "rename");
 
     DobbyHook(
         fopen_addr,
         reinterpret_cast<dobby_dummy_func_t>(&fopen_hook),
         reinterpret_cast<dobby_dummy_func_t*>(&fopen_original)
     );
+
+    DobbyHook(
+            rename_addr,
+            reinterpret_cast<dobby_dummy_func_t>(&rename_hook),
+            reinterpret_cast<dobby_dummy_func_t*>(&rename_original)
+    );
+
     #endif
 }