fix(rules): firing into melee exemption measured target-to-nearest-ally, not attacker-to-target (SRD Shooting into a Melee)

tests/test_accuracy_rules.py

@@ -338,11 +338,13 @@ def test_firing_into_melee_minus4() -> None:
     assert t.hp == 100
 
 
-def test_firing_into_melee_avoided_when_target_10ft_away() -> None:
+def test_firing_into_melee_not_avoided_when_ally_engaged_5ft_away() -> None:
     # PF1e (SRD "Attack" — Shooting or Throwing into a Melee): "If your target
     # [...] is at least 10 feet away from the nearest friendly character, you
-    # can avoid the -4 penalty" — the 10+ ft clause is 0, not -2 (the -2 is
-    # reserved for targets two size categories larger, not modeled).
+    # can avoid the -4 penalty" — the exemption is measured from the TARGET to
+    # the attacker's nearest friendly character, not from the attacker. The
+    # archer is 10 ft from the target, but the target is engaged at 5 ft by
+    # the archer's own ally (the guard) -> the -4 still applies.
     archer = _combatant("archer", ac=99, attacks=(_bow("archer", attack_bonus=8),))
     tgt = _combatant("tgt", ac=15, attacks=(_bow("tgt"),))
     guard = _combatant("guard", ac=99)
@@ -354,8 +356,32 @@ def test_firing_into_melee_avoided_when_target_10ft_away() -> None:
     )
     a, t, _g = eng._states
     result = eng.resolve_attack(a, t, a.combatant.attacks[0])
-    assert result.total == 17
+    assert result.melee_penalty == -4
+    assert result.total == 13
+    assert result.hit is False
+    assert t.hp == 100
+
+
+def test_firing_into_melee_avoided_when_nearest_ally_20ft_away() -> None:
+    # The target is engaged (a third-party melee threat stands next to it),
+    # but the attacker's nearest friendly character is 20 ft from the target
+    # -> the -4 is avoided even though the archer itself is only 5 ft away.
+    # The OLD (buggy) rule measured attacker->target/attacker->threat and
+    # would wrongly apply the -4 here.
+    archer = _combatant("archer", ac=99, attacks=(_bow("archer", attack_bonus=8),))
+    tgt = _combatant("tgt", ac=15, attacks=(_bow("tgt"),))
+    ally = _combatant("ally", ac=99)
+    raider = _combatant("raider")  # neither the archer's side nor the target's
+    eng = _engine(
+        [archer, tgt, ally, raider],
+        [(0, 0), (0, 1), (0, 5), (1, 2)],
+        ["players", "monsters", "players", "gnolls"],
+        [10, 3],
+    )
+    a, t, _al, _r = eng._states
+    result = eng.resolve_attack(a, t, a.combatant.attacks[0])
     assert result.melee_penalty == 0
+    assert result.total == 18
     assert result.hit is True
     assert result.damage == 3