From 235ac75861ba9a789c777e98841e307e2040c2be Mon Sep 17 00:00:00 2001 From: Sweet Tea Dorminy Date: Sat, 7 Nov 2026 23:33:07 -0800 Subject: [PATCH] ai/default: Square the city danger in 64 bits military_advisor_choose_build() squares unsigned city_data->danger into an int, and this wraps; for some values it wraps negative and the city is handled as needing no defence at all. The percentage 100 * qdanger / our_def wraps too. Square into a uint64_t instead and take the percentage there, so a big stack is gauged rather than clamped. There is no value where qdanger can be a negative number. See RM #2467 Signed-off-by: Sweet Tea Dorminy --- ai/default/daimilitary.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/ai/default/daimilitary.c b/ai/default/daimilitary.c index 7f96caeb02..c7bb9af845 100644 --- a/ai/default/daimilitary.c +++ b/ai/default/daimilitary.c @@ -15,6 +15,7 @@ #include #endif +#include #include /* utility */ @@ -1835,9 +1836,10 @@ struct adv_choice *military_advisor_choose_build(struct ai_type *ait, int wall_id, danger; bool build_walls = TRUE; bool def_unit_selected = FALSE; - int qdanger = city_data->danger * city_data->danger; + /* The square of a 32-bit sum needs 64 bits. */ + uint64_t qdanger = (uint64_t) city_data->danger * city_data->danger; - if (qdanger <= 0) { + if (qdanger == 0) { /* We only need these defenders because of Martial Law value */ danger = 0; build_walls = FALSE; /* Walls don't provide Martial Law */ @@ -1851,10 +1853,10 @@ struct adv_choice *military_advisor_choose_build(struct ai_type *ait, } else if (our_def == 0) { danger = 200 + urgency; } else { - danger = MIN(200, 100 * qdanger / our_def) + urgency; + danger = MIN(200, (int) (100 * qdanger / our_def)) + urgency; } } else { - danger = 100 * qdanger / our_def; + danger = (int) (100 * qdanger / our_def); } if (pcity->surplus[O_SHIELD] <= 0 && our_def != 0) { -- 2.55.0