fixed bugs spotted in review

Author: ZocoLini

dash-spv-ffi/src/config.rs

@@ -369,7 +369,11 @@ pub unsafe extern "C" fn dash_spv_ffi_config_builder_build(
     let builder = Box::from_raw(ffi_builder.inner as *mut ClientConfigBuilder);
 
     match builder.build() {
-        Ok(config) => Box::into_raw(Box::new(config.into())),
+        Ok(config) => {
+            let mut config = FFIClientConfig::from(config);
+            config.worker_threads = ffi_builder.worker_threads;
+            Box::into_raw(Box::new(config))
+        }
         Err(err) => {
             set_last_error(&format!("Failed to build config: {}", err));
             std::ptr::null_mut()

dash-spv-ffi/tests/security/test_security.rs

@@ -74,9 +74,11 @@ mod tests {
     fn test_use_after_free_prevention() {
         unsafe {
             let temp_dir = TempDir::new().unwrap();
-            let config = dash_spv_ffi_config_new(FFINetwork::Regtest);
+            let builder = dash_spv_ffi_config_builder_regtest();
             let path = CString::new(temp_dir.path().to_str().unwrap()).unwrap();
-            dash_spv_ffi_config_set_data_dir(config, path.as_ptr());
+            dash_spv_ffi_config_builder_set_data_dir(builder, path.as_ptr());
+
+            let config = dash_spv_ffi_config_builder_build(builder);
 
             let client = dash_spv_ffi_client_new(config);
             assert!(!client.is_null());
@@ -93,7 +95,7 @@ mod tests {
             dash_spv_ffi_config_destroy(config);
 
             // Using config after free should fail
-            let result = dash_spv_ffi_config_builder_set_max_peers(config, 10);
+            let result = dash_spv_ffi_config_builder_set_max_peers(builder, 10);
             assert_ne!(result, FFIErrorCode::Success as i32);
         }
     }