Fix updates in random forest model using GOSS data sample strategy

include/LightGBM/config.h

@@ -160,7 +160,6 @@ struct Config {
   // descl2 = **Note**: internally, LightGBM uses ``gbdt`` mode for the first ``1 / learning_rate`` iterations
   std::string boosting = "gbdt";
 
-  // [doc-only]
   // type = enum
   // options = bagging, goss
   // desc = ``bagging``, Randomly Bagging Sampling

src/boosting/rf.hpp

@@ -115,6 +115,12 @@ class RF : public GBDT {
     const data_size_t bag_data_cnt = data_sample_strategy_->bag_data_cnt();
     const std::vector<data_size_t, Common::AlignmentAllocator<data_size_t, kAlignedSize>>& bag_data_indices = data_sample_strategy_->bag_data_indices();
 
+    // GOSSStrategy->Bagging may modify value of bag_data_cnt_
+    if (is_use_subset && bag_data_cnt < num_data_) {
+      tmp_grad_.resize(num_data_);
+      tmp_hess_.resize(num_data_);
+    }
+
     CHECK_EQ(gradients, nullptr);
     CHECK_EQ(hessians, nullptr);
 

src/io/config_auto.cpp

@@ -673,6 +673,7 @@ std::string Config::SaveMembersToString() const {
   str_buf << "[max_depth: " << max_depth << "]\n";
   str_buf << "[min_data_in_leaf: " << min_data_in_leaf << "]\n";
   str_buf << "[min_sum_hessian_in_leaf: " << min_sum_hessian_in_leaf << "]\n";
+  str_buf << "[data_sample_strategy: " << data_sample_strategy << "]\n";
   str_buf << "[bagging_fraction: " << bagging_fraction << "]\n";
   str_buf << "[pos_bagging_fraction: " << pos_bagging_fraction << "]\n";
   str_buf << "[neg_bagging_fraction: " << neg_bagging_fraction << "]\n";