Fixes Heap-buffer-overflow READ 1 in Assimp::ObjFileParser::getFace

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=49274

code/AssetLib/Obj/ObjFileParser.cpp

@@ -440,7 +440,7 @@ void ObjFileParser::getFace(aiPrimitiveType type) {
     const bool vt = (!m_pModel->mTextureCoord.empty());
     const bool vn = (!m_pModel->mNormals.empty());
     int iPos = 0;
-    while (m_DataIt != m_DataItEnd) {
+    while (m_DataIt < m_DataItEnd) {
         int iStep = 1;
 
         if (IsLineEnd(*m_DataIt)) {

code/AssetLib/Obj/ObjTools.h

@@ -111,6 +111,9 @@ inline Char_T getNextToken(Char_T pBuffer, Char_T pEnd) {
  */
 template <class char_t>
 inline char_t skipLine(char_t it, char_t end, unsigned int &uiLine) {
+    if (it >= end)
+        return it;
+
     while (!isEndOfBuffer(it, end) && !IsLineEnd(*it)) {
         ++it;
     }