fix(hostname): go1.27 idna valid label no longer tolerates trailing d…

.golangci.yml

@@ -10,6 +10,7 @@ linters:
     - gomodguard_v2
     - godox
     - exhaustruct
+    - exhaustruct_v5
     - nlreturn
     - nonamedreturns
     - noinlineerr

default.go

@@ -119,6 +119,7 @@ func IsHostname(str string) bool {
 	}
 
 	// IDNA check
+	str, _ = strings.CutSuffix(str, ".") // tolerates trailing ".", whereas IDNA ValidateLabel rule does not
 	res, err := idnaHostChecker.ToASCII(strings.ToLower(str))
 	if err != nil || res == "" {
 		return false
@@ -1976,7 +1977,7 @@ func isISBN(str string, version int) bool {
 		for i = range isbnVersion13 - 1 {
 			checksum += factor[i%2] * int32(sanitized[i]-'0')
 		}
-		return (int32(sanitized[isbnVersion13-1]-'0'))-((decimalBase-(checksum%decimalBase))%decimalBase) == 0
+		return int32(sanitized[isbnVersion13-1]-'0')-((decimalBase-(checksum%decimalBase))%decimalBase) == 0
 	default:
 		return isISBN(str, isbnVersion10) || isISBN(str, isbnVersion13)
 	}

format.go

@@ -122,7 +122,7 @@ func (f *defaultFormats) Add(name string, strfmt Format, validator Validator) bo
 	nme := f.normalizeName(name)
 
 	tpe := reflect.TypeOf(strfmt)
-	if tpe.Kind() == reflect.Ptr {
+	if tpe.Kind() == reflect.Pointer {
 		tpe = tpe.Elem()
 	}
 
@@ -176,7 +176,7 @@ func (f *defaultFormats) DelByFormat(strfmt Format) bool {
 	defer f.Unlock()
 
 	tpe := reflect.TypeOf(strfmt)
-	if tpe.Kind() == reflect.Ptr {
+	if tpe.Kind() == reflect.Pointer {
 		tpe = tpe.Elem()
 	}
 
@@ -208,7 +208,7 @@ func (f *defaultFormats) ContainsFormat(strfmt Format) bool {
 	f.Lock()
 	defer f.Unlock()
 	tpe := reflect.TypeOf(strfmt)
-	if tpe.Kind() == reflect.Ptr {
+	if tpe.Kind() == reflect.Pointer {
 		tpe = tpe.Elem()
 	}