Fix a segfault in the wake/sleep mechanism.

The problem was that on_think can invalidate *any* iterator in the map (e.g. a spider killing a human), not just the current one.

1 files changed, 5 insertions, 7 deletions

diff --git a/src/game/game.cpp b/src/game/game.cpp
index 9d184ea..fedc403 100644
--- a/src/game/game.cpp
+++ b/src/game/game.cpp
@@ -146,13 +146,11 @@ void state_t::tick(double now_, double dt_)
 	u.d = dt;
 	dice_prng.seed(dice_prng.next() ^ u.i);
 
-	// NOTE: on_think can erase the entity from awake_entities.
-	for (auto i = awake_entities.begin(); i != awake_entities.end(); ) {
-		auto next = i;
-		next++;
-		(*i)->on_think();
-		i = next;
-	}
+	// on_think can insert/erase elements of awake_entities so iterate
+	// over a copy of it.
+	auto copy = awake_entities;
+	for (entity_t *ent : copy)
+		ent->on_think();
 }
 
 die_t::die_t(size_t sides_)