Fix nbt bugs that cannot handle tagNames contains commas

nbt/typeinfo.go

@@ -2,17 +2,26 @@ package nbt
 
 import (
 	"reflect"
+	"strings"
 	"sync"
 )
 
 type typeInfo struct {
-	tagName     string
-	nameToIndex map[string]int
+	fields      []structField
+	nameToIndex map[string]int // index of the field in struct, not previous slice
+}
+
+type structField struct {
+	name  string
+	index int
+
+	omitEmpty bool
+	list      bool
 }
 
 var tInfoMap sync.Map
 
-func getTypeInfo(typ reflect.Type) *typeInfo {
+func typeFields(typ reflect.Type) *typeInfo {
 	if ti, ok := tInfoMap.Load(typ); ok {
 		return ti.(*typeInfo)
 	}
@@ -21,6 +30,7 @@ func getTypeInfo(typ reflect.Type) *typeInfo {
 	tInfo.nameToIndex = make(map[string]int)
 	if typ.Kind() == reflect.Struct {
 		n := typ.NumField()
+		tInfo.fields = make([]structField, 0, n)
 		for i := 0; i < n; i++ {
 			f := typ.Field(i)
 			tag := f.Tag.Get("nbt")
@@ -28,7 +38,34 @@ func getTypeInfo(typ reflect.Type) *typeInfo {
 				continue // Private field
 			}
 
-			tInfo.nameToIndex[tag] = i
+			// parse tags
+			var field structField
+			name, opts, _ := strings.Cut(tag, ",")
+			if keytag := f.Tag.Get("nbtkey"); keytag != "" {
+				name = keytag
+			} else if name == "" {
+				name = f.Name
+			}
+			field.name = name
+			field.index = i
+
+			// parse options
+			for opts != "" {
+				var name string
+				name, opts, _ = strings.Cut(opts, ",")
+				switch name {
+				case "omitempty":
+					field.omitEmpty = true
+				case "list":
+					field.list = true
+				}
+			}
+			if f.Tag.Get("nbt_type") == "list" {
+				field.list = true
+			}
+			tInfo.fields = append(tInfo.fields, field)
+
+			tInfo.nameToIndex[field.name] = i
 			if _, ok := tInfo.nameToIndex[f.Name]; !ok {
 				tInfo.nameToIndex[f.Name] = i
 			}