From db7f98b78993a28100ca15134c0f8f8138e9efcf Mon Sep 17 00:00:00 2001
From: Valentin Shergin <shergin@fb.com>
Date: Tue, 10 Apr 2018 12:46:04 -0700
Subject: [PATCH] Fabric: Introducing ShadowNode::shallowSourceNode()

Summary:
The method replaces the current source node with its source node.
It's useful when we have to clone some node but don't want to change a source node pointer.

Reviewed By: fkgozali

Differential Revision: D7503384

fbshipit-source-id: 81ec64079c7e99cb9abdda2af10d85281a94e1b1
---
 ReactCommon/fabric/core/shadownode/ShadowNode.cpp | 4 ++++
 ReactCommon/fabric/core/shadownode/ShadowNode.h   | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/ReactCommon/fabric/core/shadownode/ShadowNode.cpp b/ReactCommon/fabric/core/shadownode/ShadowNode.cpp
index f15964b0b..8f54601d0 100644
--- a/ReactCommon/fabric/core/shadownode/ShadowNode.cpp
+++ b/ReactCommon/fabric/core/shadownode/ShadowNode.cpp
@@ -108,6 +108,10 @@ void ShadowNode::clearSourceNode() {
   sourceNode_.reset();
 }
 
+void ShadowNode::shallowSourceNode() {
+  sourceNode_ = sourceNode_.lock()->getSourceNode();
+}
+
 #pragma mark - Equality
 
 bool ShadowNode::operator==(const ShadowNode& rhs) const {
diff --git a/ReactCommon/fabric/core/shadownode/ShadowNode.h b/ReactCommon/fabric/core/shadownode/ShadowNode.h
index f03acb107..cd0264c22 100644
--- a/ReactCommon/fabric/core/shadownode/ShadowNode.h
+++ b/ReactCommon/fabric/core/shadownode/ShadowNode.h
@@ -67,6 +67,14 @@ public:
   void replaceChild(const SharedShadowNode &oldChild, const SharedShadowNode &newChild);
   void clearSourceNode();
 
+  /*
+   * Replaces the current source node with its source node.
+   * This method might be used for illuminating side-effects caused by the last
+   * cloning operation which are not desirable from the diffing algorithm
+   * perspective.
+   */
+  void shallowSourceNode();
+
 #pragma mark - Equality
 
   /*