Called C++ object pointer is null in economy/flag.cc

[Hans Joachim Desserud]

Called C++ object pointer is null in economy /flag.cc.

Found by scan-build. Last seen in r8227.

[SirVer (sirver)]

Setting to incomplete for bug sweeping.

[GunChleoc (gunchleoc)]

I wanted to fix this, but I don't understand why it's complaining:

if (not state) {
    Assuming 'state' is non-null

Why does it assume that state is non-null here? The condition is NOT state.

[Hans Joachim Desserud (hjd)]

I scratched my head at that one as well. I don't know how the `not` keyword works with non-booleans in C++ though, so I don't know if it simply boils down to an is-null-check.

My second puzzle is that I don't see the link between state and serial. It looks like if state is in such a state (great, overloaded terms :p) that it stays out of the first if, but enters the second, something goes wrong. But I would assume that line 87 would have a similar issue with shorter path to trigger it, but it doesn't get reported for some reason.

[GunChleoc (gunchleoc)]

get_state returns either an iterator or nullptr. nullptr evaluates to false and then will enter the alleged "Assuming 'state' is non-null" branch like it should, so I'd say that this is a false positive.

We have the same code in building.cc, seems like that one doesn't trigger anything.

[Hans Joachim Desserud (hjd)]

I've been unable to reproduce this with scan-build from LLVM 6.0 running on recent revisions. Might have been a false postive all along.