fix: the MIME type of an SVG file should be image/svg+xml

util/fsutil/file.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"io"
 	"mime/multipart"
-	"net/http"
 	"os"
 	"sync"
 
@@ -143,19 +142,16 @@ func (file *File) Save(fs WritableFS, path string, name string) (filename string
 func ParseMultipartFiles(headers []*multipart.FileHeader) ([]File, error) {
 	files := []File{}
 	for _, fh := range headers {
-		fileHeader := make([]byte, 512)
+		mimeType := "application/octet-stream"
 
 		if fh.Size != 0 {
 			f, err := fh.Open()
 			if err != nil {
 				return nil, errors.New(err)
 			}
-			if _, err := f.Read(fileHeader); err != nil {
-				_ = f.Close()
-				return nil, errors.New(err)
-			}
 
-			if _, err := f.Seek(0, 0); err != nil {
+			mimeType, err = DetectContentType(f, fh.Filename)
+			if err != nil {
 				_ = f.Close()
 				return nil, errors.New(err)
 			}
@@ -166,7 +162,7 @@ func ParseMultipartFiles(headers []*multipart.FileHeader) ([]File, error) {
 
 		file := File{
 			Header:   fh,
-			MIMEType: http.DetectContentType(fileHeader),
+			MIMEType: mimeType,
 		}
 		files = append(files, file)
 	}

util/fsutil/fsutil.go

@@ -116,7 +116,8 @@ func GetMIMEType(filesystem fs.FS, file string) (contentType string, size int64,
 
 // DetectContentType by sniffing the first 512 bytes of the given reader using `http.DetectContentType`.
 //
-// If the detected content type is `"application/octet-stream"` or `"text/plain"`, this function will attempt to
+// If the detected content type is `"application/octet-stream"`, `"text/plain"`, `"text/xml"` or
+// `"application/xml"`, this function will attempt to
 // find a more precise one using `fsutil.DetectContentTypeByExtension`.
 // The header parameter is retained (e.g: `charset=utf-8`).
 //
@@ -138,7 +139,7 @@ func DetectContentType(r io.Reader, fileName string) (string, error) {
 	}
 
 	contentType := http.DetectContentType(buffer)
-	if strings.HasPrefix(contentType, "application/octet-stream") || strings.HasPrefix(contentType, "text/plain") {
+	if strings.HasPrefix(contentType, "application/octet-stream") || strings.HasPrefix(contentType, "text/plain") || strings.HasPrefix(contentType, "text/xml") || strings.HasPrefix(contentType, "application/xml") {
 		contentType = detectContentTypeByExtension(fileName, contentType)
 	}
 	return contentType, nil
@@ -148,7 +149,7 @@ func detectContentTypeByExtension(fileName, contentType string) string {
 	for ext, t := range contentTypeByExtension {
 		if strings.HasSuffix(fileName, ext) {
 			tmp := t
-			if i := strings.Index(contentType, ";"); i != -1 {
+			if i := strings.Index(contentType, ";"); i != -1 && t != "image/svg+xml" {
 				tmp = t + contentType[i:] // Keep the "charset" arguments
 			}
 			contentType = tmp

util/fsutil/fsutil_test.go

@@ -239,6 +239,11 @@ func TestDetectContentType(t *testing.T) {
 			buf:      []byte{1, 2, 3},
 			wantMIME: "text/javascript",
 		},
+		{
+			fileName: "image.svg",
+			buf:      []byte("<?xml version=\"1.0\" encoding=\"UTF-8\"?><svg xmlns=\"http://www.w3.org/2000/svg\"></svg>"),
+			wantMIME: "image/svg+xml",
+		},
 		{
 			fileName: "eof",
 			buf:      []byte{},
@@ -300,6 +305,12 @@ func TestDetectContentTypeByExtension(t *testing.T) {
 			contentType: "text/plain; charset=utf-8",
 			fileName:    "test.css",
 		},
+		{
+			desc:        "utf8_svg",
+			want:        "image/svg+xml",
+			contentType: "text/xml; charset=utf-8",
+			fileName:    "image.svg",
+		},
 	}
 
 	for _, c := range cases {
@@ -425,6 +436,27 @@ func TestParseMultipartFiles(t *testing.T) {
 		assert.NoError(t, err)
 	})
 
+	t.Run("svg", func(t *testing.T) {
+		svgPath := toAbsolutePath("util/fsutil/test.svg")
+		err := os.WriteFile(svgPath, []byte("<?xml version=\"1.0\" encoding=\"UTF-8\"?><svg xmlns=\"http://www.w3.org/2000/svg\"></svg>"), 0644)
+		require.NoError(t, err)
+		t.Cleanup(func() {
+			deleteFile(svgPath)
+		})
+
+		form := createTestForm("util/fsutil/test.svg")
+		files, err := ParseMultipartFiles(form.File["file"])
+
+		expected := []File{
+			{
+				Header:   form.File["file"][0],
+				MIMEType: "image/svg+xml",
+			},
+		}
+		assert.Equal(t, expected, files)
+		assert.NoError(t, err)
+	})
+
 	t.Run("empty_file", func(t *testing.T) {
 		headers := []*multipart.FileHeader{
 			{