[avr-gcc-list] OT Generic C question

[Trampas]

I was helping a friend debug some code, he is new to C,  using the Keil
version of GCC for ARM. Anyway I found the following:

int i;

i=0;
i=i++;
//i was still zero that 

That is i=i++ never incremented i, now I would have thought the line would
be the same as:

i=i;
i=i+1; 

So you guys are the smartest people I know when it comes to C so I thought I
would ask you guys if this is a compiler bug or is my understanding of C
just been shaken. 

Regards,
Trampas