From 98618646f66639ddc841de388fdec216f5845f20 Mon Sep 17 00:00:00 2001
From: tqchen <tianqi.tchen@gmail.com>
Date: Thu, 26 Mar 2015 16:43:01 -0700
Subject: [PATCH] bugfix booster.check

---
 R-package/R/utils.R         | 8 ++++++--
 R-package/src/xgboost_R.cpp | 3 +++
 R-package/src/xgboost_R.h   | 6 ++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/R-package/R/utils.R b/R-package/R/utils.R
index 9674ae9be..3c1ffdd20 100644
--- a/R-package/R/utils.R
+++ b/R-package/R/utils.R
@@ -87,8 +87,12 @@ xgb.handleToBooster <- function(handle)
 # Check whether an xgb.Booster object is complete
 xgb.Booster.check <- function(bst, saveraw = TRUE)
 {
-  if (is.null(bst$handle)) {
-    bst$handle <- xgb.load(bst$raw)
+  isnull <- is.null(bst$handle)
+  if (!isnull) {
+    isnull <- .Call("XGCheckNullPtr_R", bst$handle, PACKAGE="xgboost")
+  }
+  if (isnull) {
+    bst$handle <- xgb.Booster(modelfile = bst$raw)
   } else {
     if (is.null(bst$raw) && saveraw)
       bst$raw <- xgb.save.raw(bst$handle)
diff --git a/R-package/src/xgboost_R.cpp b/R-package/src/xgboost_R.cpp
index 315b6c2c1..a2ca9536f 100644
--- a/R-package/src/xgboost_R.cpp
+++ b/R-package/src/xgboost_R.cpp
@@ -59,6 +59,9 @@ inline void _WrapperEnd(void) {
 }
 
 extern "C" {
+  SEXP XGCheckNullPtr_R(SEXP handle) {
+    return ScalarLogical(R_ExternalPtrAddr(handle) == NULL);
+  }
   void _DMatrixFinalizer(SEXP ext) {    
     if (R_ExternalPtrAddr(ext) == NULL) return;
     XGDMatrixFree(R_ExternalPtrAddr(ext));
diff --git a/R-package/src/xgboost_R.h b/R-package/src/xgboost_R.h
index a86e85ffa..61b84a80e 100644
--- a/R-package/src/xgboost_R.h
+++ b/R-package/src/xgboost_R.h
@@ -11,6 +11,12 @@ extern "C" {
 }
 
 extern "C" {
+  /*!
+   * \brief check whether a handle is NULL
+   * \param handle
+   * \return whether it is null ptr
+   */
+  SEXP XGCheckNullPtr_R(SEXP handle);
   /*!
    * \brief load a data matrix 
    * \param fname name of the content