From 7ebee9de1838e3d3954ecd36d43db499dd508a17 Mon Sep 17 00:00:00 2001
From: Balazs OROSZI <orobalage@gmail.com>
Date: Thu, 12 Oct 2017 20:42:34 +0200
Subject: [PATCH] Skip creating snaphots if there was no change. WARNING: ONLY
 FOR TESTING, POSSIBLE LOSS OF DATA, YOU HAVE BEEN WARNED!

---
 internal/archiver/archiver.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/internal/archiver/archiver.go b/internal/archiver/archiver.go
index 055c4626d5f..9d304549cf6 100644
--- a/internal/archiver/archiver.go
+++ b/internal/archiver/archiver.go
@@ -766,6 +766,14 @@ func (arch *Archiver) Snapshot(ctx context.Context, p *restic.Progress, paths, t
 		return nil, restic.ID{}, errors.Fatal("no files/dirs saved, refusing to create empty snapshot")
 	}
 
+	psn, err := restic.LoadSnapshot(ctx, arch.repo, *sn.Parent)
+	if err != nil {
+		return nil, restic.ID{}, err
+	}
+	if root.Subtree.Equal(*psn.Tree) {
+		return nil, restic.ID{}, errors.Fatal("tree matches parent, not creating snapshot")
+	}
+
 	// save index
 	err = arch.repo.SaveIndex(ctx)
 	if err != nil {