Editor crashes due to file operations in code

Development Programming & Scripting
1

Hi, I have a BlueprintFunctionLibrary I’m writing and some of the code I have is causing the editor to crash on startup.

I have a blueprint-friendly function that does nothing but call a constructor for a separate class and return it.

MyClass MyBlueprintFunction(FString filename) {
   MyClass instance;
   instance = MyClass(TCHAR_TO_ANSI(*filename));
   return instance;
}

MyClass’ constructor tries to construct itself using information from the file provided.

In the constructor I have the following code:

MyClass(char *filename) {
  FILE *file;
  fopen_s(&file, filename, "rb");  // from stdio.h
  ...  // (using the file)
}

This code compiles fine in Visual Studio 2015 for development editor. When I use the File* for any operations later in the function, the editor crashes when I start it up. If I remove all uses of the File* the editor does not crash. Some examples of my uses of the File* are as follows:

uint32_t width = 0, height = 0;
...
fread(&width, 1, sizeof(width), file);
fread(&height, 1, sizeof(height), file);
fclose(file);

Leaving any of these lines (except the first) in the function causes the editor to crash. Any ideas of what I might be doing wrong? Is this a bug?

2

Are you checking the return of the open function to see if it opened successfully? Or to see if the file pointer is null?

3

Nope, I added some checking to catch that case and now everything works, thanks!