fix encoding with map key contains colon character (#604)

Author: goccy

encode.go

@@ -538,6 +538,17 @@ func (e *Encoder) isNeedQuoted(v string) bool {
 	if e.isFlowStyle && strings.ContainsAny(v, `]},'"`) {
 		return true
 	}
+	if e.isFlowStyle {
+		for i := 0; i < len(v); i++ {
+			if v[i] != ':' {
+				continue
+			}
+			if i+1 < len(v) && v[i+1] == '/' {
+				continue
+			}
+			return true
+		}
+	}
 	if token.IsNeedQuoted(v) {
 		return true
 	}

encode_test.go

@@ -8,6 +8,7 @@ import (
 	"math"
 	"reflect"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -1654,3 +1655,23 @@ b:
 		t.Fatalf("failed to encode. expected %s but got %s", expected, got)
 	}
 }
+
+type Issue174 struct {
+	K string
+	V []int
+}
+
+func (v Issue174) MarshalYAML() ([]byte, error) {
+	return yaml.MarshalWithOptions(map[string][]int{v.K: v.V}, yaml.Flow(true))
+}
+
+func TestIssue174(t *testing.T) {
+	b, err := yaml.Marshal(Issue174{"00:00:00-23:59:59", []int{1, 2, 3}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := strings.TrimSuffix(string(b), "\n")
+	if got != `{"00:00:00-23:59:59": [1, 2, 3]}` {
+		t.Fatalf("failed to encode: %q", got)
+	}
+}