[command.package] validate chart name before packaging

Signed-off-by: Debdut Chakraborty <debdut.chakraborty@rocket.chat>

.gitignore

@@ -10,3 +10,4 @@ bin/
 vendor/
 # Ignores charts pulled for dependency build tests
 cmd/helm/testdata/testcharts/issue-7233/charts/*
+testchart/

pkg/action/package.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"regexp"
 	"syscall"
 
 	"github.com/Masterminds/semver/v3"
@@ -61,6 +62,10 @@ func (p *Package) Run(path string, vals map[string]interface{}) (string, error)
 		return "", err
 	}
 
+	if matched, _ := regexp.MatchString("^[[:lower:][:digit:]-]+$", ch.Name()); !matched {
+		return "", errors.New(fmt.Sprintf("Invalid chart name \"%s\". Chart names must be lower case letters and numbers with optionally dashes (-) for separator\n", ch.Name()))
+	}
+
 	// If version is set, modify the version.
 	if p.Version != "" {
 		ch.Metadata.Version = p.Version