> This causes GCC to complain thusly:
>
>
> ```
> 2018-07-10T04:59:38.6368270Z ref-filter.c:1477:6: error: variable 'eaten' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> 2018-07-10T04:59:38.6468620Z if (oi->info.contentp) {
> 2018-07-10T04:59:38.6568710Z ^~~~~~~~~~~~~~~~~
> 2018-07-10T04:59:38.6669970Z ref-filter.c:1489:7: note: uninitialized use occurs here
> 2018-07-10T04:59:38.6774240Z if (!eaten)
> 2018-07-10T04:59:38.6874860Z ^~~~~
> 2018-07-10T04:59:38.6976740Z ref-filter.c:1477:2: note: remove the 'if' if its condition is always true
> 2018-07-10T04:59:38.7072330Z if (oi->info.contentp) {
> 2018-07-10T04:59:38.7172760Z ^~~~~~~~~~~~~~~~~~~~~~~
> 2018-07-10T04:59:38.7274040Z ref-filter.c:1466:11: note: initialize the variable 'eaten' to silence this warning
> 2018-07-10T04:59:38.7374670Z int eaten;
> 2018-07-10T04:59:38.7474870Z ^
> 2018-07-10T04:59:38.7575690Z = 0
> ```
>
> (See
> https://mseng.visualstudio.com/VSOnline/_build/results?buildId=6640204&view=logs
> for details)
>
> I think that GCC is correct, and at the same time, it isn't. Because it
> does not matter whether `eaten` is uninitialized here:
It's undefined behaviour; 'eaten' is int, and an int may have padding
bits and trap representations.
> if it is, then
> `buf` is NULL, and the `free(buf);` call does nothing in particular.
