Merge pull request 'issue点击图片查看，非下载' (#623) from show-issue-pic into V20211101

Reviewed-on: https://git.openi.org.cn/OpenI/aiforge/pulls/623
Reviewed-by: ychao_1983 <ychao_1983@sina.com>

routers/repo/attachment.go

@@ -278,7 +278,21 @@ func GetAttachment(ctx *context.Context) {
 			ctx.ServerError("Update", err)
 			return
 		}
-		http.Redirect(ctx.Resp, ctx.Req.Request, url, http.StatusMovedPermanently)
+		if dataSet != nil {
+			http.Redirect(ctx.Resp, ctx.Req.Request, url, http.StatusMovedPermanently)
+		} else {
+			fr, err := storage.Attachments.Open(attach.RelativePath())
+			if err != nil {
+				ctx.ServerError("Open", err)
+				return
+			}
+			defer fr.Close()
+			if err = ServeData(ctx, attach.Name, fr); err != nil {
+				ctx.ServerError("ServeData", err)
+				return
+			}
+		}
+
 	} else {
 		fr, err := storage.Attachments.Open(attach.RelativePath())
 		if err != nil {