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Fix signed integer overflow when initialising scheduled dispatch

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When date * daylength is too large for int32
This commit is contained in:
Jonathan G Rennison
2021-04-18 11:05:24 +01:00
parent 74091c3c80
commit 1da8f1a229
1 changed files with 20 additions and 2 deletions
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22
src/schdispatch_cmd.cpp
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@@ -310,9 +310,25 @@ void OrderList::RemoveScheduledDispatch(uint32 offset)
void OrderList::UpdateScheduledDispatch()
{
bool update_windows = false;
if (this->GetScheduledDispatchStartTick() == 0) {
int64 start = _scaled_date_ticks - (_scaled_date_ticks % this->GetScheduledDispatchDuration());
SchdispatchConvertToFullDateFract(
start,
&this->scheduled_dispatch_start_date, &this->scheduled_dispatch_start_full_date_fract);
int64 last_dispatch = -start;
if (last_dispatch < INT_MIN && _settings_game.game_time.time_in_minutes) {
/* Advance by multiples of 24 hours */
const int64 day = 24 * 60 * _settings_game.game_time.ticks_per_minute;
this->scheduled_dispatch_last_dispatch = last_dispatch + (CeilDivT<int64>(INT_MIN - last_dispatch, day) * day);
} else {
this->scheduled_dispatch_last_dispatch = ClampToI32(last_dispatch);
}
}
/* Most of the time this loop does not runs. It makes sure start date in in past */
while (this->GetScheduledDispatchStartTick() > _scaled_date_ticks) {
this->scheduled_dispatch_last_dispatch += this->GetScheduledDispatchDuration();
OverflowSafeInt32 last_dispatch = this->scheduled_dispatch_last_dispatch;
last_dispatch += this->GetScheduledDispatchDuration();
this->scheduled_dispatch_last_dispatch = last_dispatch;
SchdispatchConvertToFullDateFract(
this->GetScheduledDispatchStartTick() - this->GetScheduledDispatchDuration(),
&this->scheduled_dispatch_start_date, &this->scheduled_dispatch_start_full_date_fract);
@@ -320,7 +336,9 @@ void OrderList::UpdateScheduledDispatch()
}
/* Most of the time this loop runs once. It makes sure the start date is as close to current time as possible. */
while (this->GetScheduledDispatchStartTick() + this->GetScheduledDispatchDuration() <= _scaled_date_ticks) {
this->scheduled_dispatch_last_dispatch -= this->GetScheduledDispatchDuration();
OverflowSafeInt32 last_dispatch = this->scheduled_dispatch_last_dispatch;
last_dispatch -= this->GetScheduledDispatchDuration();
this->scheduled_dispatch_last_dispatch = last_dispatch;
SchdispatchConvertToFullDateFract(
this->GetScheduledDispatchStartTick() + this->GetScheduledDispatchDuration(),
&this->scheduled_dispatch_start_date, &this->scheduled_dispatch_start_full_date_fract);