// unscomp.c
// show problem with linux/fs/buffer.c and unsigned comparisons
                                    
#include <stdio.h>    // printf
int main()
{
  unsigned long size;
  long offset;

  size = 1024;
  offset = 50;

  if ((offset -= size) >= 0) { 
    // 50 - 1024 is negative
    printf("no -- this is wrong\n");
    return 2;
  }

  // Now a similar thing. The result of the subtraction is unsigned
  // and so is the comparison
  offset = 50;
  if(offset - size < 0) {
    printf("This is also wrong\n"); return 3;
  }

  printf("yes this is right\n");
  return 0;
}