Why does writing to STD_OUTPUT_HANDLE crash under Sublime Text?

Question

I have an application which happens to log to the console using winapi's WriteFile on a handle acquired from GetStdHandle. Minimal test case:

#include <Windows.h>

int main(int argc, char** argv) {
  HANDLE console = GetStdHandle(STD_OUTPUT_HANDLE);
  if(GetFileType(console) == FILE_TYPE_UNKNOWN)
    return;
  WriteFile(console, "abc", 3, 0, 0);
}

built with default options in VS2013. This works without problems when invoked on a standard Windows console and when invoked from python2/python3/Sublime's console using e.g. subprocess.Popen('/path/to/my.exe').

Now I want to run this program as a build system in SublimeText 3. This is the build definition:

{
  "cmd": [ "/path/to/my.exe" ]
}

According to documentation this should sort of be equivalent to using subprocess.Popen. However when I invoke this 'build system' Sublime's output pane displays abc and then the call to WriteFile crashes with

0xC0000005: Access violation writing location 0x00000000.

What happens here? Is this a problem in my code, in Sublime, or in WriteFile? Anything that can be done about it? (I tried using shell_cmd instead of cmd but that makes no difference)

Answer 1

You are passing the wrong arguments to WriteFile:

lpNumberOfBytesWritten [out, optional]
This parameter can be NULL only when the lpOverlapped parameter is not NULL.

For a synchronous call to WriteFile, you will have to pass a valid pointer to a DWORD, where the number of bytes written are returned:

#include <Windows.h>

int main(int argc, char** argv) {
  HANDLE console = GetStdHandle(STD_OUTPUT_HANDLE);
  if(GetFileType(console) == FILE_TYPE_UNKNOWN)
    return;
  DWORD dwBytesWritten{};
  WriteFile(console, "abc", 3, &dwBytesWritten, 0);
}