From 03f34824b49e83864e4fd39c7aa793d2018fa896 Mon Sep 17 00:00:00 2001
From: tqchen <tianqi.tchen@gmail.com>
Date: Wed, 11 Mar 2015 09:43:42 -0700
Subject: [PATCH] some potential fix

---
 src/gbm/gbtree-inl.hpp |  8 ++++----
 src/tree/model.h       | 10 ++++++----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/gbm/gbtree-inl.hpp b/src/gbm/gbtree-inl.hpp
index 66b03dd87..d2ff2358b 100644
--- a/src/gbm/gbtree-inl.hpp
+++ b/src/gbm/gbtree-inl.hpp
@@ -69,11 +69,11 @@ class GBTree : public IGradBooster {
       trees[i]->SaveModel(fo);
     }
     if (tree_info.size() != 0) {
-      fo.Write(&tree_info[0], sizeof(int) * tree_info.size());
+      fo.Write(BeginPtr(tree_info), sizeof(int) * tree_info.size());
     }
     if (mparam.num_pbuffer != 0 && with_pbuffer) {
-      fo.Write(&pred_buffer[0], pred_buffer.size() * sizeof(float));
-      fo.Write(&pred_counter[0], pred_counter.size() * sizeof(unsigned));
+      fo.Write(BeginPtr(pred_buffer), pred_buffer.size() * sizeof(float));
+      fo.Write(BeginPtr(pred_counter), pred_counter.size() * sizeof(unsigned));
     }
   }
   // initialize the predic buffer
@@ -99,7 +99,7 @@ class GBTree : public IGradBooster {
                        std::vector<bst_gpair> *in_gpair) {
     const std::vector<bst_gpair> &gpair = *in_gpair;
     std::vector<std::vector<tree::RegTree*> > new_trees;
-    if (mparam.num_output_group == 1) {      
+    if (mparam.num_output_group == 1) {
       new_trees.push_back(BoostNewTrees(gpair, p_fmat, buffer_offset, info, 0));
     } else {
       const int ngroup = mparam.num_output_group;
diff --git a/src/tree/model.h b/src/tree/model.h
index 4d325ea8c..4eea34911 100644
--- a/src/tree/model.h
+++ b/src/tree/model.h
@@ -296,9 +296,10 @@ class TreeModel {
     utils::Check(fi.Read(&param, sizeof(Param)) > 0,
                  "TreeModel: wrong format");
     nodes.resize(param.num_nodes); stats.resize(param.num_nodes);
-    utils::Check(fi.Read(&nodes[0], sizeof(Node) * nodes.size()) > 0,
+    utils::Assert(param.num_nodes != 0, "invalid model"); 
+    utils::Check(fi.Read(BeginPtr(nodes), sizeof(Node) * nodes.size()) > 0,
                  "TreeModel: wrong format");
-    utils::Check(fi.Read(&stats[0], sizeof(NodeStat) * stats.size()) > 0,
+    utils::Check(fi.Read(BeginPtr(stats), sizeof(NodeStat) * stats.size()) > 0,
                  "TreeModel: wrong format");
     if (param.size_leaf_vector != 0) {
       utils::Check(fi.Read(&leaf_vector), "TreeModel: wrong format");
@@ -322,8 +323,9 @@ class TreeModel {
     utils::Assert(param.num_nodes == static_cast<int>(stats.size()),
                   "Tree::SaveModel");
     fo.Write(&param, sizeof(Param));
-    fo.Write(&nodes[0], sizeof(Node) * nodes.size());
-    fo.Write(&stats[0], sizeof(NodeStat) * nodes.size());
+    utils::Assert(param.num_nodes != 0, "invalid model"); 
+    fo.Write(BeginPtr(nodes), sizeof(Node) * nodes.size());
+    fo.Write(BeginPtr(stats), sizeof(NodeStat) * nodes.size());
     if (param.size_leaf_vector != 0) fo.Write(leaf_vector);
   }
   /*!