database/gredis: When using the ScriptExists method, if Redis crashes or the connection is down, there will be an index out of range issue that causes the program to crash.

[CampbellChen]

Go version

go version go1.22.1 linux/amd64

GoFrame version

v2.7.1

Can this bug be reproduced with the latest release?

Option Yes

What did you do?

main.go

package main

import (
	_ "github.com/gogf/gf/contrib/nosql/redis/v2"

	"crypto/sha1"
	"encoding/hex"
	"io"

	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/os/gctx"
)

const scriptLck = `
local flg = tostring(KEYS[1])
local exp = tonumber(ARGV[1])
local uid = tostring(ARGV[2])
local res = redis.call('GET', flg)
if res then
  return 0
else
  redis.call('SETEX', flg, exp, uid)
  return 1
end
`

func main() {
	_sha1 := hash(scriptLck)
	ctx := gctx.New()
	exists, err := g.Redis().ScriptExists(ctx, _sha1)
	if err != nil {
		g.Log().Errorf(ctx, "[sync.lock] error checking script (%s) existence: %+v", _sha1, err)
	}
	if len(exists) > 0 && exists[_sha1] {
		g.Log().Infof(ctx, "[sync.lock] script (%s) already exists", _sha1)
	} else {
		g.Log().Infof(ctx, "[sync.lock] script (%s) not exists.", _sha1)
	}
}

// hash generates SHA-1 hash for the given string.
func hash(k string) string {
	h := sha1.New()
	_, _ = io.WriteString(h, k)
	return hex.EncodeToString(h.Sum(nil))
}

What did you see happen?

During the execution of the above code, if a Redis outage occurs or the Redis connection is unavailable, an index out of range error will occur, causing the service to crash.

2024-06-17 15:30:52.327 [FATA] {d8d390f526bad9174ce6096d32e970ee} exception recovered: runtime error: index out of range [0] with length 0
1. exception recovered: runtime error: index out of range [0] with length 0
   1).  go.opentelemetry.io/otel/sdk/trace.(*recordingSpan).End.deferwrap1
        C:/Users/Administrator/go/pkg/mod/go.opentelemetry.io/otel/sdk@v1.25.0/trace/span.go:381
   2).  go.opentelemetry.io/otel/sdk/trace.(*recordingSpan).End
        C:/Users/Administrator/go/pkg/mod/go.opentelemetry.io/otel/sdk@v1.25.0/trace/span.go:413

What did you expect to see?

Upon debug, it was found that the ScriptExists method under the database/gredis package does not check for null values and index bounds before using the returned values.

Pls fix it. Tks!