Fix some mp3/mp4 media files show as Raw

modules/setting/mime_type_map.go

@@ -4,7 +4,10 @@
 
 package setting
 
-import "strings"
+import (
+	"mime"
+	"strings"
+)
 
 // MimeTypeMap defines custom mime type mapping settings
 var MimeTypeMap = struct {
@@ -21,6 +24,7 @@ func newMimeTypeMap() {
 	m := make(map[string]string, len(keys))
 	for _, key := range keys {
 		m[strings.ToLower(key.Name())] = key.Value()
+		_ = mime.AddExtensionType(key.Name(), key.Value())
 	}
 	MimeTypeMap.Map = m
 	if len(keys) > 0 {

modules/typesniffer/typesniffer.go

@@ -7,7 +7,9 @@ package typesniffer
 import (
 	"fmt"
 	"io"
+	"mime"
 	"net/http"
+	"path/filepath"
 	"regexp"
 	"strings"
 
@@ -87,6 +89,26 @@ func DetectContentType(data []byte) SniffedType {
 	return SniffedType{ct}
 }
 
+func DetectContentTypeExtFirst(name string, readSeekerOrBytes interface{}) (SniffedType, error) {
+	// we can merge `setting.MimeTypeMap` by mime.AddExtensionType()
+	ct := mime.TypeByExtension(filepath.Ext(name))
+	if ct != "" && !strings.Contains(ct, "text/") {
+		return SniffedType{ct}, nil
+	}
+	if r, ok := readSeekerOrBytes.(io.ReadSeeker); ok {
+		st, err := DetectContentTypeFromReader(r)
+		if nil != err {
+			return SniffedType{}, err
+		}
+		_, err = r.Seek(0, io.SeekStart)
+		if nil != err {
+			return SniffedType{}, err
+		}
+		return st, nil
+	}
+	return DetectContentType(readSeekerOrBytes.([]byte)), nil
+}
+
 // DetectContentTypeFromReader guesses the content type contained in the reader.
 func DetectContentTypeFromReader(r io.Reader) (SniffedType, error) {
 	buf := make([]byte, sniffLen)

routers/common/repo.go

@@ -63,6 +63,7 @@ func ServeData(ctx *context.Context, name string, size int64, reader io.Reader)
 	// Google Chrome dislike commas in filenames, so let's change it to a space
 	name = strings.ReplaceAll(name, ",", " ")
 
+	// st, err := typesniffer.DetectContentTypeExtFirst(name, buf)
 	st := typesniffer.DetectContentType(buf)
 
 	mappedMimeType := ""

routers/web/repo/view.go

@@ -427,7 +427,7 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 				}
 				buf = buf[:n]
 
-				st = typesniffer.DetectContentType(buf)
+				st, _ = typesniffer.DetectContentTypeExtFirst(blob.Name(), buf)
 				isTextFile = st.IsText()
 
 				fileSize = meta.Size