Self assignment is used to silence overly aggressive and incorrect uninitialized warnings in GCC (esp prior to 4.5).
I'm not sure if thats what the code there is doing— not enough context, but I'd guess it's likely. Odd that the author hasn't seen that before.
Another one that I've seen quite often is casting to void.
E.g. in older GCC you would get int x; switch (!!foo) { case 0:x=0;break; case 1:x=1;break; /no default/ } print(..x)
Or many other cases and the compiler will give an erroneous uninitialized warning. you can assign x to itself at the stop to eliminate the warning without changing the generated code.