From eba327b9c0dc9516c733db4eb47f1b16428753f8 Mon Sep 17 00:00:00 2001
From: Max Limper <max.limper@igd.fraunhofer.de>
Date: Mon, 9 Jul 2018 12:19:33 +0200
Subject: [PATCH 1/2] make tester fail for issue 177 failing  (explicit MTL
 base dir given by API user)

---
 tests/tester.cc | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tests/tester.cc b/tests/tester.cc
index 82748fa..638507d 100644
--- a/tests/tester.cc
+++ b/tests/tester.cc
@@ -768,14 +768,20 @@ TEST_CASE("invalid-face-definition", "[face]") {
   REQUIRE(0 == shapes[0].mesh.indices.size());
 }
 
-TEST_CASE("Empty mtl basedir", "[Issue177]") {
-  // Win32 spesific?
+TEST_CASE("Empty mtl basedir", "[Issue177]") {  
   tinyobj::attrib_t attrib;
   std::vector<tinyobj::shape_t> shapes;
   std::vector<tinyobj::material_t> materials;
-
+    
   std::string err;
-  bool ret = tinyobj::LoadObj(&attrib, &shapes, &materials, &err, "issue-177.obj");
+  
+  // A case where the user explicitly provides an empty string
+  // Win32 specific?
+  const char * userBaseDir = "";
+  bool ret = tinyobj::LoadObj(&attrib, &shapes, &materials, &err, "issue-177.obj", userBaseDir);
+  
+  // if mtl loading fails, we get an error message (WARN) here
+  ret &= err.empty();
 
   if (!err.empty()) {
     std::cerr << "[Issue177] " << err << std::endl;

From c4e7e65acb76dae671fd0e51a7742aeaf7ed9161 Mon Sep 17 00:00:00 2001
From: Max Limper <max.limper@igd.fraunhofer.de>
Date: Mon, 9 Jul 2018 12:21:46 +0200
Subject: [PATCH 2/2] fixed #177 (explicit empty mtl base dir given)

---
 tiny_obj_loader.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tiny_obj_loader.h b/tiny_obj_loader.h
index 9e43a7d..7b9f342 100644
--- a/tiny_obj_loader.h
+++ b/tiny_obj_loader.h
@@ -1736,9 +1736,8 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
     return false;
   }
 
-  std::string baseDir;
-  if (mtl_basedir) {
-    baseDir = mtl_basedir;
+  std::string baseDir = mtl_basedir ? mtl_basedir : "";
+  if (!baseDir.empty()) {    
 #ifndef _WIN32
     const char dirsep = '/';
 #else