[twoodfin]

benmmurphy's comment below points out that the flawed test was "mode > 0".

https://news.ycombinator.com/item?id=13470516

[zokier]

I'd still expect GCC to warn about that

[0xffff2]

Warn about what? "mode > 0" is not always true.

[twoodfin]

Eh, I feel like I've seen even pickier static analysis warnings. If the next -Wall told me I should rewrite this as "mode != 0" to confirm the intent, that wouldn't seem crazy to me.