From 06a78d0cea159e0e7cf52559c19be629101a3998 Mon Sep 17 00:00:00 2001
From: Fabian Fritzsche <mail@fabian-fritzsche.de>
Date: Fri, 3 Jul 2020 02:22:30 +0200
Subject: [PATCH] Added preview bypass for .gif files

---
 http/preview.go | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/http/preview.go b/http/preview.go
index 060d60eb..8619adae 100644
--- a/http/preview.go
+++ b/http/preview.go
@@ -3,6 +3,7 @@ package http
 import (
 	"fmt"
 	"image"
+	"image/gif"
 	"net/http"
 
 	"github.com/disintegration/imaging"
@@ -79,6 +80,18 @@ func handleImagePreview(w http.ResponseWriter, r *http.Request, file *files.File
 	}
 	defer fd.Close()
 
+	if format == imaging.GIF && size == sizeBig {
+		g, err := gif.DecodeAll(fd)
+		if err != nil {
+			return errToStatus(err), err
+		}
+
+		if gif.EncodeAll(w, g) != nil {
+			return errToStatus(err), err
+		}
+		return 0, nil
+	}
+
 	img, err := imaging.Decode(fd, imaging.AutoOrientation(true))
 	if err != nil {
 		return errToStatus(err), err