package main

import "math"

func main() {
	for i := 0; i < 100; i++ {
		f()
	}
}
func f() {
	// Allocate map.
	m := map[float64]int{}
	// Fill to just before a growth trigger.
	const N = 13 << 4 // 6.5 * 2 * 2^k
	for i := 0; i < N; i++ {
		m[math.NaN()] = i
	}
	// Trigger growth.
	m[math.NaN()] = N

	// Iterate through map.
	i := 0
	for _, v := range m {
		if i == 6 {
			// Partway through iteration, clear the map.
			clear(m)
		} else if i > 6 {
			// If we advance to the next iteration, that's a bug.
			println("BAD", i, v)
		}
		i++
	}
}