switch timespan mult/div to use doubles until creating the timespan

src/main/java/ch/njol/skript/classes/data/DefaultOperations.java

@@ -99,21 +99,24 @@ public class DefaultOperations {
 		// Timespan - Number
 		// Number - Timespan
 		Arithmetics.registerOperation(Operator.MULTIPLICATION, Timespan.class, Number.class, (left, right) -> {
-			long scalar = right.longValue();
-			if (scalar < 0)
+			double scalar = right.doubleValue();
+			if (scalar < 0 || !Double.isFinite(scalar))
 				return null;
-			return new Timespan(Math2.multiplyClamped(left.getAs(TimePeriod.MILLISECOND), scalar));
+			double value = left.getAs(TimePeriod.MILLISECOND) * scalar;
+			return new Timespan((long) Math.min(value, Long.MAX_VALUE));
 		}, (left, right) -> {
-			long scalar = left.longValue();
-			if (scalar < 0)
+			double scalar = left.doubleValue();
+			if (scalar < 0 || !Double.isFinite(scalar))
 				return null;
-			return new Timespan(scalar * right.getAs(TimePeriod.MILLISECOND));
+			double value = right.getAs(TimePeriod.MILLISECOND) * scalar;
+			return new Timespan((long) Math.min(value, Long.MAX_VALUE));
 		});
 		Arithmetics.registerOperation(Operator.DIVISION, Timespan.class, Number.class, (left, right) -> {
-			long scalar = right.longValue();
-			if (scalar <= 0)
+			double scalar = right.doubleValue();
+			if (scalar < 0 || !Double.isFinite(scalar))
 				return null;
-			return new Timespan(left.getAs(TimePeriod.MILLISECOND) / scalar);
+			double value = left.getAs(TimePeriod.MILLISECOND) / scalar;
+			return new Timespan((long) Math.min(value, Long.MAX_VALUE));
 		});
 
 		// Timespan / Timespan = Number

src/test/skript/tests/regressions/7645-floating point timespan math.sk

@@ -0,0 +1,12 @@
+options:
+	max-timespan: 9223372036854775807 milliseconds
+
+test "floating point timespan math":
+	assert (0.9 * 5 seconds) is 4.5 seconds with "failed basic floating point multiplication"
+	assert (1 * 5 seconds) is 5 seconds with "failed basic integer multiplication"
+	assert (0.0 * 5 seconds) is 0 seconds with "failed multiplication by 0"
+	assert (5 seconds / 5) is 1 seconds with "failed integer division"
+	assert (5 seconds / 2.5) is 2 seconds with "failed floating point division"
+	assert (5 seconds / infinity value) is not set with "Division by infinity unexpectedly returned real value"
+
+	assert (5 seconds * 10 ^ 308) is {@max-timespan} with "failed to clamp to the long max value"