fix: slice append lose the data for NSScanner

[jiuker]

Community Contribution License

All community contributions in this pull request are licensed to the project maintainers
under the terms of the Apache 2 license.
By creating this pull request I represent that I have the right to license the
contributions to the project maintainers under the Apache 2 license.

Description

fix: slice append lose the data

package main

import (
	"fmt"
	"sync"
)

func main() {
	for j := 0; j < 10; j++ {
		s := []string{}
		wg := sync.WaitGroup{}
		mu := sync.Mutex{}
		for i := 0; i < 50; i++ {
			wg.Add(1)
			s = append(s, "")
			go func(i int) {
				defer wg.Done()
				mu.Lock()
				s[i] = fmt.Sprintf("%d", i)
				mu.Unlock()
			}(len(s) - 1)
		}
		wg.Wait()
		if index, ok := check(s); ok {
			fmt.Println(s, index)
		}
	}
}

func check(datas []string) (int, bool) {
	for index, data := range datas {
		if data == "" {
			return index, true
		}
	}
	return 0, false
}

will show some slice will lose the data.

[0  2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49] 1

Motivation and Context

How to test this PR?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Unit tests added/updated
• Internal documentation updated
• Create a documentation update request here

[vadmeste]

LGTM