1 files changed, 21 insertions, 0 deletions
diff --git a/routers/repo/middlewares.go b/routers/repo/middlewares.go
index 94e007cd20..757a049ab7 100644
--- a/routers/repo/middlewares.go
+++ b/routers/repo/middlewares.go
@@ -21,3 +21,24 @@ func SetEditorconfigIfExists(ctx *context.Context) {
 
 	ctx.Data["Editorconfig"] = ec
 }
+
+func SetDiffViewStyle(ctx *context.Context) {
+	var (
+		userStyle  = ctx.User.DiffViewStyle
+		queryStyle = ctx.Query("style")
+		style      string
+	)
+
+	if queryStyle == "unified" || queryStyle == "split" {
+		style = queryStyle
+	} else if userStyle == "unified" || userStyle == "split" {
+		style = userStyle
+	} else {
+		style = "unified"
+	}
+
+	ctx.Data["IsSplitStyle"] = style == "split"
+	if err := ctx.User.UpdateDiffViewStyle(style); err != nil {
+		ctx.Handle(500, "ErrUpdateDiffViewStyle", err)
+	}
+}