How did the bug manifest itself? You can store 0xffffffff(ffffffff) in a 32(64)-bit unsigned int, or a 32(64)-bit signed int. In the one case you'll get UINT_MAX, -1 in the other, but they should compare as equal. If you have -Wextra turned on, gcc will give a warning, though.

Here's some sample C code tested on a 32-bit Linux system:

  #include <stdio.h>
  
  int main(int argc, char *argv[])
  {
          unsigned int val1 = 0xffffffff;
  
          printf("val1 == -1: %d\n", val1 == -1);
  
          return 0;
  }

The result:

  val1 == -1: 1