Fix UNKNOWN READ in Assimp::MDLImporter::InternReadFile_Quake1

code/AssetLib/MDL/MDLLoader.cpp

@@ -271,10 +271,16 @@ void MDLImporter::InternReadFile(const std::string &pFile,
     }
 }
 
+// ------------------------------------------------------------------------------------------------
+// Check whether we're still inside the valid file range
+bool MDLImporter::IsPosValid(const void *szPos) {
+    return szPos && (const unsigned char *)szPos <= this->mBuffer + this->iFileSize && szPos >= this->mBuffer;
+}
+
 // ------------------------------------------------------------------------------------------------
 // Check whether we're still inside the valid file range
 void MDLImporter::SizeCheck(const void *szPos) {
-    if (!szPos || (const unsigned char *)szPos > this->mBuffer + this->iFileSize || szPos < this->mBuffer) {
+    if (!IsPosValid(szPos)) {
         throw DeadlyImportError("Invalid MDL file. The file is too small "
                                 "or contains invalid data.");
     }
@@ -284,7 +290,7 @@ void MDLImporter::SizeCheck(const void *szPos) {
 // Just for debugging purposes
 void MDLImporter::SizeCheck(const void *szPos, const char *szFile, unsigned int iLine) {
     ai_assert(nullptr != szFile);
-    if (!szPos || (const unsigned char *)szPos > mBuffer + iFileSize) {
+    if (!IsPosValid(szPos)) {
         // remove a directory if there is one
         const char *szFilePtr = ::strrchr(szFile, '\\');
         if (!szFilePtr) {

code/AssetLib/MDL/MDLLoader.h

@@ -150,6 +150,7 @@ protected:
     */
     void SizeCheck(const void* szPos);
     void SizeCheck(const void* szPos, const char* szFile, unsigned int iLine);
+    bool IsPosValid(const void* szPos);
 
     // -------------------------------------------------------------------
     /** Validate the header data structure of a game studio MDL7 file