Fix #100

Former-commit-id: 1130e6e7ae67fdcb866c5dc4eee11de28fc69a96 [formerly 55dc3c0c9bf3b07608f8cade510e2d0d94782ab3] [formerly d5a48b8bef9ae5cc613558b15e98d584a5ed6fa5 [formerly cacca2e6f2]]
Former-commit-id: cd6f80f2a273d1fa5ed5d35924e416bed7c64194 [formerly d9b42a6d8f025a26107ba91ece5cc4855a2cb681]
Former-commit-id: 2f28d37577a16078e1c191192dfba7ae2b9f2acd

file.go

@@ -209,14 +209,22 @@ func (i *file) RetrieveFileType(checkContent bool) error {
 	mimetype := mime.TypeByExtension(i.Extension)
 
 	if mimetype == "" && checkContent {
-		content, err = ioutil.ReadFile(i.Path)
+		file, err := os.Open(i.Path)
 		if err != nil {
 			return err
 		}
+		defer file.Close()
+
+		// Only the first 512 bytes are used to sniff the content type.
+		buffer := make([]byte, 512)
+		_, err = file.Read(buffer)
+		if err != nil && err != io.EOF {
+			return err
+		}
 
 		// Tries to get the file mimetype using its first
 		// 512 bytes.
-		mimetype = http.DetectContentType(content)
+		mimetype = http.DetectContentType(buffer)
 	}
 
 	if strings.HasPrefix(mimetype, "video") {
@@ -249,7 +257,7 @@ func (i *file) RetrieveFileType(checkContent bool) error {
 	for _, extension := range textExtensions {
 		if strings.HasSuffix(i.Name, extension) {
 			i.Type = "text"
-			return nil
+			goto End
 		}
 	}