(svn r10212) -Fix [FS#723]: money overflow bugs in many locations.

1 files changed, 15 insertions, 3 deletions

diff --git a/src/command.cpp b/src/command.cpp
index 31c0d417e..8b814d034 100644
--- a/src/command.cpp
+++ b/src/command.cpp
@@ -594,7 +594,7 @@ callb_err:
 
 CommandCost CommandCost::AddCost(CommandCost ret)
 {
-	this->cost += ret.cost;
+	this->AddCost(ret.cost);
 	if (this->success && !ret.success) {
 		this->message = ret.message;
 		this->success = false;
@@ -604,13 +604,25 @@ CommandCost CommandCost::AddCost(CommandCost ret)
 
 CommandCost CommandCost::AddCost(Money cost)
 {
-	this->cost += cost;
+	/* Overflow protection */
+	if (cost < 0 && (this->cost + cost) > this->cost) {
+		this->cost = INT64_MIN;
+	} else if (cost > 0 && (this->cost + cost) < this->cost) {
+		this->cost = INT64_MAX;
+	} else  {
+		this->cost += cost;
+	}
 	return *this;
 }
 
 CommandCost CommandCost::MultiplyCost(int factor)
 {
-	this->cost *= factor;
+	/* Overflow protection */
+	if (factor != 0 && (INT64_MAX / myabs(factor)) < myabs(this->cost)) {
+		this->cost = (this->cost < 0 == factor < 0) ? INT64_MAX : INT64_MIN;
+	} else {
+		this->cost *= factor;
+	}
 	return *this;
 }