When `apply_force_damage` was called to damage a robot, it tested if the
`ctype.laser_info.parent_signature` of the other object matched
`ConsoleObject->signature` and, if so, awarded points to the console
player. This allowed the player to sometimes get points for ramming a
robot to death, but was buggy. When the player rams a robot, the player
is the other object, so accessing `ctype.laser_info` is wrong.
Historically, the player's signature was zero and player
`ctype.laser_info.parent_signature` (an inactive and therefore incorrect
branch of the union) happened to be zero, so the test succeeded. Commit
44753209d6 changed the layout of
`struct player_info` such that
`ConsoleObject->ctype.laser_info.parent_signature` was not zero, causing
the player not to be his own parent. Prior to this commit, the player
could still wrongly fail the test if the `player_info` member that
aliased `laser_info.parent_signature` was nonzero. In the commit
preceding the obvious break, `player_info.player_flags` aliased
`laser_info.parent_signature`, so a player with certain flags (such as
invulnerability) would wrongly fail the test. The exact manifestation
has changed over time as `struct player_info` gained members.
Restructure the test so that a ramming kill always awards points,
without checking ancestry.
Reported-by: Descender1032 <https://forum.dxx-rebirth.com/showthread.php?tid=1006> (no commit identifiers given)
Fixes: 44753209d6 ("Move homing_object_dist to object.ctype.player_info")
bcb3f6b486