Freeciv

Hmm seems wrong for flagless units. They should be not airliftable neither to ally cities at all nor to own cities with ally units.

Ouch, misplaced the ? : branches.

Also, may we allow the clients to try airlift to any unseen city in hope that an ally conquered it (at least if we have a live ally)?

S3_1 patch uses nullptr:

../../src/common/unit.c: In function ‘test_unit_can_airlift_to’:
../../src/common/unit.c:94:33: error: ‘nullptr’ undeclared (first use in this function); did you mean ‘nullptr_t’?
94 | const struct tile *dst_tile = nullptr; | ^_~~~~ | nullptr_t

hmm happens 3.3 and 3.2 also use it, but they somehow compiled at my installation.

nullptr is being defined even in S3_2, though our CodingStyle was (later) defined to prefer it in S3_3 and later only, and to avoid it in S3_2.

Marko Lindqvist wrote in #note-13:

though our CodingStyle was (later) defined to prefer it in S3_3

Does it mean the patch for main can go for 3.3?

Alexandr Ignatiev wrote in #note-14:

Marko Lindqvist wrote in #note-13:

though our CodingStyle was (later) defined to prefer it in S3_3

Does it mean the patch for main can go for 3.3?

They both should have nullptr instead of NULL, if that's what you are asking.