From 7576e1c61d3ecaf0ba1a679197c438d84de4f6a9 Mon Sep 17 00:00:00 2001
From: Pritesh Nandgaonkar <prit91@fb.com>
Date: Thu, 23 May 2019 03:46:25 -0700
Subject: [PATCH] Fix watch tab bug

Summary:
This solves the watch tab crash discussed here D15266478, which got reverted.

Bug: [Here](diffusion/FBS/browse/master/xplat/sonar/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutPlugin/FlipperKitLayoutPlugin.mm;57c596a566bec49e343af51b93df65ed1377a2b9$338), when the node is `CKComponentRootView` the `[descriptor childForNode: node atIndex: i]` returns `SKComponentLayoutWrapper`. In the next iteration of the loop, node is `SKComponentLayoutWrapper`, the  `[descriptor childForNode: node atIndex: i]` returns `CKComponentRootView`, and hence the infinite recursion

I also tested T44431259, it is not regressed.

Reviewed By: passy

Differential Revision: D15451821

fbshipit-source-id: 25f10112f5f52bb1fa964316a4c7e91a3b29156d
---
 .../SKComponentLayoutDescriptor.mm                       | 3 +++
 .../SKComponentLayoutWrapper.h                           | 2 +-
 .../SKComponentLayoutWrapper.mm                          | 9 +++++++--
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutDescriptor.mm b/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutDescriptor.mm
index b39ed7be9..966528d8a 100644
--- a/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutDescriptor.mm
+++ b/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutDescriptor.mm
@@ -86,6 +86,9 @@
 
 - (id)childForNode:(SKComponentLayoutWrapper *)node atIndex:(NSUInteger)index {
     if (node.children.size() == 0) {
+      if (node.rootNode == node.component.viewContext.view) {
+        return nil;
+      }
       return node.component.viewContext.view;
     }
     return node.children[index];
diff --git a/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.h b/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.h
index a7d4c8da4..5f7513fe1 100644
--- a/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.h
+++ b/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.h
@@ -18,7 +18,7 @@
 @property (nonatomic, readonly) CGSize size;
 @property (nonatomic, readonly) CGPoint position;
 @property (nonatomic, readonly) std::vector<SKComponentLayoutWrapper *> children;
-
+@property (nonatomic, readonly) id<CKInspectableView> rootNode;
 // Null for layouts which are not direct children of a CKFlexboxComponent
 @property (nonatomic, readonly) BOOL isFlexboxChild;
 @property (nonatomic, readonly) CKFlexboxComponentChild flexboxChild;
diff --git a/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.mm b/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.mm
index b6d9999bd..4fded345c 100644
--- a/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.mm
+++ b/iOS/Plugins/FlipperKitLayoutPlugin/FlipperKitLayoutComponentKitSupport/SKComponentLayoutWrapper.mm
@@ -58,7 +58,8 @@ static CKFlexboxComponentChild findFlexboxLayoutParams(CKComponent *parent, CKCo
   [[SKComponentLayoutWrapper alloc] initWithLayout:layout
                                           position:CGPointMake(0, 0)
                                          parentKey:[NSString stringWithFormat: @"%p.", layout.component]
-                                      reuseWrapper:reuseWrapper];
+                                      reuseWrapper:reuseWrapper
+                                              rootNode: root];
   // Cache the result.
   if (layout.component) {
     objc_setAssociatedObject(layout.component, &kLayoutWrapperKey, wrapper, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
@@ -70,8 +71,10 @@ static CKFlexboxComponentChild findFlexboxLayoutParams(CKComponent *parent, CKCo
                       position:(CGPoint)position
                      parentKey:(NSString *)parentKey
                   reuseWrapper:(CKComponentReuseWrapper *)reuseWrapper
+                          rootNode:(id<CKInspectableView>)node
 {
   if (self = [super init]) {
+    _rootNode = node;
     _component = layout.component;
     _size = layout.size;
     _position = position;
@@ -93,7 +96,9 @@ static CKFlexboxComponentChild findFlexboxLayoutParams(CKComponent *parent, CKCo
         SKComponentLayoutWrapper *childWrapper = [[SKComponentLayoutWrapper alloc] initWithLayout:child.layout
                                                                                          position:child.position
                                                                                         parentKey:[_identifier stringByAppendingFormat:@"[%d].", index++]
-                                                                                     reuseWrapper:reuseWrapper];
+                                                                                     reuseWrapper:reuseWrapper
+                                                                                             rootNode: nil
+                                                  ];
         childWrapper->_isFlexboxChild = [_component isKindOfClass:[CKFlexboxComponent class]];
         childWrapper->_flexboxChild = findFlexboxLayoutParams(_component, child.layout.component);
         _children.push_back(childWrapper);