Prohibited NaN steps.

libraries/stdlib/src/kotlin/Ranges.kt

@@ -139,11 +139,13 @@ public fun LongRange.step(step: Long): LongProgression {
 }
 
 public fun FloatRange.step(step: Float): FloatProgression {
+    if (java.lang.Float.isNaN(step)) throw IllegalArgumentException("Step must not be NaN")
     checkStepIsPositive(step > 0, step)
     return FloatProgression(start, end, step)
 }
 
 public fun DoubleRange.step(step: Double): DoubleProgression {
+    if (java.lang.Double.isNaN(step)) throw IllegalArgumentException("Step must not be NaN")
     checkStepIsPositive(step > 0, step)
     return DoubleProgression(start, end, step)
 }

libraries/stdlib/test/language/RangeTest.kt

@@ -184,5 +184,15 @@ public class RangeTest {
         failsWith(javaClass<IllegalArgumentException>()) { 'z' downTo 'a' step -2 }
         failsWith(javaClass<IllegalArgumentException>()) { 0.0 downTo -5.0 step -0.5 }
         failsWith(javaClass<IllegalArgumentException>()) { 0.0.toFloat() downTo -5.0.toFloat() step -0.5.toFloat() }
+
+        // NaN increment or step
+        failsWith(javaClass<IllegalArgumentException>()) { DoubleProgression(0.0, 5.0, jDouble.NaN) }
+        failsWith(javaClass<IllegalArgumentException>()) { FloatProgression(0.0.toFloat(), 5.0.toFloat(), jFloat.NaN) }
+
+        failsWith(javaClass<IllegalArgumentException>()) { 0.0..5.0 step jDouble.NaN }
+        failsWith(javaClass<IllegalArgumentException>()) { 0.0.toFloat()..5.0.toFloat() step jFloat.NaN }
+
+        failsWith(javaClass<IllegalArgumentException>()) { 5.0 downTo 0.0 step jDouble.NaN }
+        failsWith(javaClass<IllegalArgumentException>()) { 5.0.toFloat() downTo 0.0.toFloat() step jFloat.NaN }
     }
 }

runtime/src/jet/DoubleProgression.java

@@ -25,6 +25,9 @@ public class DoubleProgression implements Progression<Double> {
     private final double increment;
 
     public DoubleProgression(double start, double end, double increment) {
+        if (Double.isNaN(increment)) {
+            throw new IllegalArgumentException("Increment must be not NaN");
+        }
         if (increment == 0.0 || increment == -0.0) {
             throw new IllegalArgumentException("Increment must be non-zero: " + increment);
         }

runtime/src/jet/FloatProgression.java

@@ -25,6 +25,9 @@ public class FloatProgression implements Progression<Float> {
     private final float increment;
 
     public FloatProgression(float start, float end, float increment) {
+        if (Float.isNaN(increment)) {
+            throw new IllegalArgumentException("Increment must be not NaN");
+        }
         if (increment == 0.0f || increment == -0.0f) {
             throw new IllegalArgumentException("Increment must be non-zero: " + increment);
         }