title: mingw error with fopen() in shared folder
body: <p>I have an issue in my C-Project. I'm trying to write an existing file on an nas-server with fopen(name,"w"), but I get an null-pointer. fopen(name,"r") works fine. I have all 
  permissions on the server. The thrown error is 22 (invalid argument). Here is my code:</p>
  
  <pre><code>fp = fopen("N:\\TEST-DTE\\USER.3\\ROOT\\#DESKTOP", "w");
  if(fp)
  {
      fprintf(fp, "Hello\n");
      fclose(fp);
  }
  else
  {
      printf("%s\n", strerror(errno));
      fflush(stdout);
  }
  </code></pre>