From 397f5efdc6851097d7d0ec61391d4d67ffdb11f2 Mon Sep 17 00:00:00 2001
From: greg7mdp <greg7mdp@gmail.com>
Date: Thu, 21 Jul 2022 14:12:20 -0400
Subject: [PATCH] Do a move instead of a copy in `SHAMapInnerNode::setChild`

---
 src/ripple/shamap/SHAMapInnerNode.h        | 2 +-
 src/ripple/shamap/impl/SHAMap.cpp          | 6 +++---
 src/ripple/shamap/impl/SHAMapInnerNode.cpp | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/ripple/shamap/SHAMapInnerNode.h b/src/ripple/shamap/SHAMapInnerNode.h
index 5f0765e9c26..c85cdcbbc85 100644
--- a/src/ripple/shamap/SHAMapInnerNode.h
+++ b/src/ripple/shamap/SHAMapInnerNode.h
@@ -147,7 +147,7 @@ class SHAMapInnerNode final : public SHAMapTreeNode,
     getChildHash(int m) const;
 
     void
-    setChild(int m, std::shared_ptr<SHAMapTreeNode> const& child);
+    setChild(int m, std::shared_ptr<SHAMapTreeNode> child);
 
     void
     shareChild(int m, std::shared_ptr<SHAMapTreeNode> const& child);
diff --git a/src/ripple/shamap/impl/SHAMap.cpp b/src/ripple/shamap/impl/SHAMap.cpp
index 6f6acb9a7e1..d68d3896f13 100644
--- a/src/ripple/shamap/impl/SHAMap.cpp
+++ b/src/ripple/shamap/impl/SHAMap.cpp
@@ -118,7 +118,7 @@ SHAMap::dirtyUp(
         assert(branch >= 0);
 
         node = unshareNode(std::move(node), nodeID);
-        node->setChild(branch, child);
+        node->setChild(branch, std::move(child));
 
         child = std::move(node);
     }
@@ -718,7 +718,7 @@ SHAMap::delItem(uint256 const& id)
         stack.pop();
 
         node = unshareNode(std::move(node), nodeID);
-        node->setChild(selectBranch(nodeID, id), prevNode);
+        node->setChild(selectBranch(nodeID, id), std::move(prevNode));
 
         if (!nodeID.isRoot())
         {
@@ -796,7 +796,7 @@ SHAMap::addGiveItem(SHAMapNodeType type, std::shared_ptr<SHAMapItem const> item)
         int branch = selectBranch(nodeID, tag);
         assert(inner->isEmptyBranch(branch));
         auto newNode = makeTypedLeaf(type, std::move(item), cowid_);
-        inner->setChild(branch, newNode);
+        inner->setChild(branch, std::move(newNode));
     }
     else
     {
diff --git a/src/ripple/shamap/impl/SHAMapInnerNode.cpp b/src/ripple/shamap/impl/SHAMapInnerNode.cpp
index d408fe195f1..6ea6f47eb37 100644
--- a/src/ripple/shamap/impl/SHAMapInnerNode.cpp
+++ b/src/ripple/shamap/impl/SHAMapInnerNode.cpp
@@ -284,7 +284,7 @@ SHAMapInnerNode::getString(const SHAMapNodeID& id) const
 
 // We are modifying an inner node
 void
-SHAMapInnerNode::setChild(int m, std::shared_ptr<SHAMapTreeNode> const& child)
+SHAMapInnerNode::setChild(int m, std::shared_ptr<SHAMapTreeNode> child)
 {
     assert((m >= 0) && (m < branchFactor));
     assert(cowid_ != 0);
@@ -310,7 +310,7 @@ SHAMapInnerNode::setChild(int m, std::shared_ptr<SHAMapTreeNode> const& child)
         auto const childIndex = *getChildIndex(m);
         auto [_, hashes, children] = hashesAndChildren_.getHashesAndChildren();
         hashes[childIndex].zero();
-        children[childIndex] = child;
+        children[childIndex] = std::move(child);
     }
 
     hash_.zero();