update go samples

Author: wing328

samples/client/petstore/go/go-petstore/client.go

@@ -17,6 +17,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"mime/multipart"
 	"net/http"
@@ -381,6 +382,15 @@ func (c *APIClient) decode(v interface{}, b []byte, contentType string) (err err
 		*s = string(b)
 		return nil
 	}
+	if f, ok := v.(**os.File); ok {
+		*f, err = ioutil.TempFile("", "HttpClientFile")
+		if err != nil {
+			return
+		}
+		_, err = (*f).Write(b)
+		_, err = (*f).Seek(0, io.SeekStart)
+		return
+	}
 	if xmlCheck.MatchString(contentType) {
 		if err = xml.Unmarshal(b, v); err != nil {
 			return err

samples/openapi3/client/petstore/go/go-petstore/client.go

@@ -17,6 +17,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"mime/multipart"
 	"net/http"
@@ -384,6 +385,15 @@ func (c *APIClient) decode(v interface{}, b []byte, contentType string) (err err
 		*s = string(b)
 		return nil
 	}
+	if f, ok := v.(**os.File); ok {
+		*f, err = ioutil.TempFile("", "HttpClientFile")
+		if err != nil {
+			return
+		}
+		_, err = (*f).Write(b)
+		_, err = (*f).Seek(0, io.SeekStart)
+		return
+	}
 	if xmlCheck.MatchString(contentType) {
 		if err = xml.Unmarshal(b, v); err != nil {
 			return err