From cda38e03ed8a6dc407319e1363ad710f581de662 Mon Sep 17 00:00:00 2001
From: Selmar Kok <skok@asobostudio.com>
Date: Wed, 22 Aug 2018 18:26:10 +0200
Subject: [PATCH 1/2] change from warning to error for missing bin files

---
 tiny_gltf.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tiny_gltf.h b/tiny_gltf.h
index fb8070d..d00be44 100644
--- a/tiny_gltf.h
+++ b/tiny_gltf.h
@@ -1257,8 +1257,8 @@ static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
 
   std::string filepath = FindFile(paths, filename, fs);
   if (filepath.empty() || filename.empty()) {
-    if (warn) {
-      (*warn) += "File not found : " + filename + "\n";
+    if (err) {
+      (*err) += "File not found : " + filename + "\n";
     }
     return false;
   }

From e3b3fa9eb663468e96f200754eed9b003501ef4f Mon Sep 17 00:00:00 2001
From: Selmar Kok <skok@asobostudio.com>
Date: Wed, 22 Aug 2018 19:04:21 +0200
Subject: [PATCH 2/2] add required parameter to LoadExternalFile

---
 tiny_gltf.h | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/tiny_gltf.h b/tiny_gltf.h
index d00be44..3d18c48 100644
--- a/tiny_gltf.h
+++ b/tiny_gltf.h
@@ -1238,7 +1238,7 @@ std::string base64_decode(std::string const &encoded_string) {
 
 static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
                              std::string *warn, const std::string &filename,
-                             const std::string &basedir, size_t reqBytes,
+                             const std::string &basedir, bool required, size_t reqBytes,
                              bool checkSize, FsCallbacks *fs) {
   if (fs == nullptr || fs->FileExists == nullptr ||
       fs->ExpandFilePath == nullptr || fs->ReadWholeFile == nullptr) {
@@ -1249,6 +1249,8 @@ static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
     return false;
   }
 
+  std::string* failMsgOut = required ? err : warn;
+
   out->clear();
 
   std::vector<std::string> paths;
@@ -1257,8 +1259,8 @@ static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
 
   std::string filepath = FindFile(paths, filename, fs);
   if (filepath.empty() || filename.empty()) {
-    if (err) {
-      (*err) += "File not found : " + filename + "\n";
+    if (failMsgOut) {
+      (*failMsgOut) += "File not found : " + filename + "\n";
     }
     return false;
   }
@@ -1268,15 +1270,17 @@ static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
   bool fileRead =
       fs->ReadWholeFile(&buf, &fileReadErr, filepath, fs->user_data);
   if (!fileRead) {
-    if (err) {
-      (*err) += "File read error : " + filepath + " : " + fileReadErr + "\n";
+    if (failMsgOut) {
+      (*failMsgOut) += "File read error : " + filepath + " : " + fileReadErr + "\n";
     }
     return false;
   }
 
   size_t sz = buf.size();
   if (sz == 0) {
-    (*err) += "File is empty : " + filepath + "\n";
+    if(failMsgOut) {
+      (*failMsgOut) += "File is empty : " + filepath + "\n";
+	}
     return false;
   }
 
@@ -1288,8 +1292,8 @@ static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
       std::stringstream ss;
       ss << "File size mismatch : " << filepath << ", requestedBytes "
          << reqBytes << ", but got " << sz << std::endl;
-      if (err) {
-        (*err) += ss.str();
+      if (failMsgOut) {
+        (*failMsgOut) += ss.str();
       }
       return false;
     }
@@ -2171,7 +2175,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
 #ifdef TINYGLTF_NO_EXTERNAL_IMAGE
     return true;
 #endif
-    if (!LoadExternalFile(&img, err, warn, uri, basedir, 0, false, fs)) {
+    if (!LoadExternalFile(&img, err, warn, uri, basedir, false, 0, false, fs)) {
       if (warn) {
         (*warn) += "Failed to load external 'uri' for image parameter\n";
       }
@@ -2266,7 +2270,7 @@ static bool ParseBuffer(Buffer *buffer, std::string *err, const json &o,
       } else {
         // External .bin file.
         if (!LoadExternalFile(&buffer->data, err, /* warn */ nullptr, buffer->uri,
-                              basedir, bytes, true, fs)) {
+                              basedir, true, bytes, true, fs)) {
           return false;
         }
       }
@@ -2308,7 +2312,7 @@ static bool ParseBuffer(Buffer *buffer, std::string *err, const json &o,
     } else {
       // Assume external .bin file.
       if (!LoadExternalFile(&buffer->data, err, /* warn */ nullptr, buffer->uri,
-                            basedir, bytes, true, fs)) {
+                            basedir, true, bytes, true, fs)) {
         return false;
       }
     }