fix integer overflow in mapgen (#11641)

[dragonfireclient.git] / src / mapgen / mapgen.cpp

diff --git a/src/mapgen/mapgen.cpp b/src/mapgen/mapgen.cpp
index d767bd264dd350b8741842581ed4719ada575e64..1f2ac491e952331e41aac3249760d5d18be5c3f7 100644 (file)
--- a/src/mapgen/mapgen.cpp
+++ b/src/mapgen/mapgen.cpp
@@ -238,7 +238,8 @@ u32 Mapgen::getBlockSeed(v3s16 p, s32 seed)
 
 u32 Mapgen::getBlockSeed2(v3s16 p, s32 seed)
 {
-       u32 n = 1619 * p.X + 31337 * p.Y + 52591 * p.Z + 1013 * seed;
+       // Multiply by unsigned number to avoid signed overflow (UB)
+       u32 n = 1619U * p.X + 31337U * p.Y + 52591U * p.Z + 1013U * seed;
        n = (n >> 13) ^ n;
        return (n * (n * n * 60493 + 19990303) + 1376312589);
 }