From 9e84bb38a8ca9f2e3ce9d7045f74634685657f1a Mon Sep 17 00:00:00 2001
From: JoelKatz <DavidJoelSchwartz@GMail.com>
Date: Sun, 14 Oct 2012 23:14:17 -0700
Subject: [PATCH] Add new 'isEmpty' function to find empty inner nodes.

---
 src/SHAMap.h        |  1 +
 src/SHAMapNodes.cpp | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/SHAMap.h b/src/SHAMap.h
index 079ddf0c0c..6d579a918d 100644
--- a/src/SHAMap.h
+++ b/src/SHAMap.h
@@ -195,6 +195,7 @@ public:
 	bool isInnerNode() const { return !mItem; }
 	bool setChildHash(int m, const uint256& hash);
 	bool isEmptyBranch(int m) const { return !mHashes[m]; }
+	bool isEmpty() const;
 	int getBranchCount() const;
 	void makeInner();
 	const uint256& getChildHash(int m) const
diff --git a/src/SHAMapNodes.cpp b/src/SHAMapNodes.cpp
index db35686759..12f4c956e1 100644
--- a/src/SHAMapNodes.cpp
+++ b/src/SHAMapNodes.cpp
@@ -364,7 +364,7 @@ void SHAMapTreeNode::addRaw(Serializer& s, SHANodeFormat format)
 
 	if (mType == tnINNER)
 	{
-		assert(getBranchCount() != 0);
+		assert(!isEmpty());
 		if (format == snfPREFIX)
 		{
 			s.add32(sHP_InnerNode);
@@ -453,6 +453,14 @@ SHAMapItem::pointer SHAMapTreeNode::getItem() const
 	return boost::make_shared<SHAMapItem>(*mItem);
 }
 
+bool SHAMapTreeNode::isEmpty() const
+{
+	assert(isInner());
+	for (int i = 0; i < 16; ++i)
+		if (mHashes[i].isNonZero()) return false;
+	return true;
+}
+
 int SHAMapTreeNode::getBranchCount() const
 {
 	assert(isInner());