SPIGOT-6017: BoundingBox#rayTrace returns incorrect null

By: blablubbabc <lukas@wirsindwir.de>

paper-api/src/main/java/org/bukkit/util/BoundingBox.java

@@ -844,12 +844,14 @@ public class BoundingBox implements Cloneable, ConfigurationSerializable {
         double startZ = start.getZ();
 
         // ray direction:
-        Vector dir = direction.clone().normalize();
+        Vector dir = direction.clone().normalizeZeros().normalize();
         double dirX = dir.getX();
         double dirY = dir.getY();
         double dirZ = dir.getZ();
 
         // saving a few divisions below:
+        // Note: If one of the direction vector components is 0.0, these
+        // divisions result in infinity. But this is not a problem.
         double divX = 1.0D / dirX;
         double divY = 1.0D / dirY;
         double divZ = 1.0D / dirZ;

paper-api/src/main/java/org/bukkit/util/Vector.java

@@ -365,6 +365,19 @@ public class Vector implements Cloneable, ConfigurationSerializable {
         return this;
     }
 
+    /**
+     * Converts each component of value <code>-0.0</code> to <code>0.0</code>.
+     *
+     * @return This vector.
+     */
+    @NotNull
+    Vector normalizeZeros() {
+        if (x == -0.0D) x = 0.0D;
+        if (y == -0.0D) y = 0.0D;
+        if (z == -0.0D) z = 0.0D;
+        return this;
+    }
+
     /**
      * Returns whether this vector is in an axis-aligned bounding box.
      * <p>