From bcc36cc1b2a8e90a1bc2142b8615c84afc81b31c Mon Sep 17 00:00:00 2001
From: Mingwei Pan <mingwei@fb.com>
Date: Fri, 15 Sep 2017 08:22:36 -0700
Subject: [PATCH] Zero out all fields in YGZeroOutLayoutRecursivly using memset

Summary:
Add a new test named YGZeroOutLayoutRecursivlyTest, which verifies that padding and margin of a child node should be set to 0 when the display is set to none.
Modify YGZeroOutLayoutRecursivly function, use memset to clear the layout struct of the node.

Reviewed By: emilsjolander

Differential Revision: D5842351

fbshipit-source-id: d2c2b6f829588a200525b7ccbdb63003cb4dcc4e
---
 tests/YGZeroOutLayoutRecursivlyTest.cpp | 39 +++++++++++++++++++++++++
 yoga/Yoga.c                             | 13 +--------
 2 files changed, 40 insertions(+), 12 deletions(-)
 create mode 100644 tests/YGZeroOutLayoutRecursivlyTest.cpp

diff --git a/tests/YGZeroOutLayoutRecursivlyTest.cpp b/tests/YGZeroOutLayoutRecursivlyTest.cpp
new file mode 100644
index 00000000..9d38a3a3
--- /dev/null
+++ b/tests/YGZeroOutLayoutRecursivlyTest.cpp
@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#include <gtest/gtest.h>
+#include <yoga/Yoga.h>
+
+TEST(YogaTest, zero_out_layout) {
+  const YGNodeRef root = YGNodeNew();
+  YGNodeStyleSetFlexDirection(root, YGFlexDirectionRow);
+  YGNodeStyleSetWidth(root, 200);
+  YGNodeStyleSetHeight(root, 200);
+
+  const YGNodeRef child = YGNodeNew();
+  YGNodeInsertChild(root, child, 0);
+  YGNodeStyleSetWidth(child, 100);
+  YGNodeStyleSetHeight(child, 100);
+  YGNodeStyleSetMargin(child, YGEdgeTop, 10);
+  YGNodeStyleSetPadding(child, YGEdgeTop, 10);
+
+  YGNodeCalculateLayout(root, 100, 100, YGDirectionLTR);
+
+  ASSERT_FLOAT_EQ(10, YGNodeLayoutGetMargin(child, YGEdgeTop));
+  ASSERT_FLOAT_EQ(10, YGNodeLayoutGetPadding(child, YGEdgeTop));
+
+  YGNodeStyleSetDisplay(child, YGDisplayNone);
+
+  YGNodeCalculateLayout(root, 100, 100, YGDirectionLTR);
+
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetMargin(child, YGEdgeTop));
+  ASSERT_FLOAT_EQ(0, YGNodeLayoutGetPadding(child, YGEdgeTop));
+
+  YGNodeFreeRecursive(root);
+}
diff --git a/yoga/Yoga.c b/yoga/Yoga.c
index 15ac4586..84aa5a75 100644
--- a/yoga/Yoga.c
+++ b/yoga/Yoga.c
@@ -1865,18 +1865,7 @@ static bool YGNodeFixedSizeSetMeasuredDimensions(const YGNodeRef node,
 }
 
 static void YGZeroOutLayoutRecursivly(const YGNodeRef node) {
-  node->layout.dimensions[YGDimensionHeight] = 0;
-  node->layout.dimensions[YGDimensionWidth] = 0;
-  node->layout.position[YGEdgeTop] = 0;
-  node->layout.position[YGEdgeBottom] = 0;
-  node->layout.position[YGEdgeLeft] = 0;
-  node->layout.position[YGEdgeRight] = 0;
-  node->layout.cachedLayout.availableHeight = 0;
-  node->layout.cachedLayout.availableWidth = 0;
-  node->layout.cachedLayout.heightMeasureMode = YGMeasureModeExactly;
-  node->layout.cachedLayout.widthMeasureMode = YGMeasureModeExactly;
-  node->layout.cachedLayout.computedWidth = 0;
-  node->layout.cachedLayout.computedHeight = 0;
+  memset(&(node->layout), 0, sizeof(YGLayout));
   node->hasNewLayout = true;
   const uint32_t childCount = YGNodeGetChildCount(node);
   for (uint32_t i = 0; i < childCount; i++) {