Fail early if trying to read a string larger than the nif file size.

This is much better than failing after a few minutes with an out of memory error.

components/nif/nifstream.cpp

@@ -83,6 +83,11 @@ Transformation NIFStream::getTrafo()
 
 std::string NIFStream::getString(size_t length)
 {
+    //Make sure we're not reading in too large of a string
+    unsigned int fileSize = inp->size();
+    if(fileSize != 0 && fileSize < length)
+        file->fail("Attempted to read a string with " + Ogre::StringConverter::toString(length) + "characters , but file is only "+Ogre::StringConverter::toString(fileSize)+ "bytes!");
+
     std::vector<char> str (length+1, 0);
 
     if(inp->read(&str[0], length) != length)