From 5391e2972a28d1638347bc9c5fa9b3ef24bac551 Mon Sep 17 00:00:00 2001
From: Pavel Kalinnikov <pkalinnikov@google.com>
Date: Mon, 5 Jul 2021 08:06:23 -0400
Subject: [PATCH] Don't store the ephemeral node hashes

They are not used for reads, everything is based on compact ranges which
don't use the ephemeral nodes.
---
 log/sequencer.go      |  4 ++--
 log/sequencer_test.go | 12 ------------
 2 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/log/sequencer.go b/log/sequencer.go
index 27dc75199b..6cff64b42a 100644
--- a/log/sequencer.go
+++ b/log/sequencer.go
@@ -187,8 +187,8 @@ func updateCompactRange(cr *compact.Range, leaves []*trillian.LogLeaf, label str
 			return nil, nil, err
 		}
 	}
-	// Store ephemeral nodes on the right border of the tree as well.
-	hash, err := cr.GetRootHash(store)
+	// Note: The ephemeral node hashes are not stored.
+	hash, err := cr.GetRootHash(nil)
 	if err != nil {
 		return nil, nil, err
 	}
diff --git a/log/sequencer_test.go b/log/sequencer_test.go
index a93e671bec..ba9520afda 100644
--- a/log/sequencer_test.go
+++ b/log/sequencer_test.go
@@ -99,10 +99,6 @@ var (
 			ID:   compact.NewNodeID(0, 16),
 			Hash: testonly.MustDecodeBase64("L5Iyd7aFOVewxiRm29xD+EU+jvEo4RfufBijKdflWMk="),
 		},
-		{
-			ID:   compact.NewNodeID(5, 0),
-			Hash: testonly.MustDecodeBase64("R57DrKTGuZdjCNXjv6InGrm4rABLOn9yWpdHmYOoLwU="),
-		},
 	}
 
 	testRoot = &types.LogRootV1{
@@ -128,14 +124,6 @@ var (
 	}
 	// Nodes that will be stored after updating the tree of size 21.
 	updatedNodes21 = []tree.Node{
-		{
-			ID:   compact.NewNodeID(5, 0),
-			Hash: testonly.MustDecodeBase64("1oUtLDlyOWXLHLAvL3NvWaO4D9kr0oQYScylDlgjey4="),
-		},
-		{
-			ID:   compact.NewNodeID(3, 2),
-			Hash: testonly.MustDecodeBase64("1yCvo/9xbNIileBAEjc+c00GxVQQV7h54Tdmkc48uRU="),
-		},
 		{
 			ID:   compact.NewNodeID(1, 10),
 			Hash: testonly.MustDecodeBase64("S55qEsQMx90/eq1fSb87pYCB9WIYL7hBgiTY+B9LmPw="),