From 035808e750a17caca5f36df6c8ef80b1a5e0658c Mon Sep 17 00:00:00 2001
From: Scott Wolchok <swolchok@fb.com>
Date: Fri, 8 Feb 2019 13:36:43 -0800
Subject: [PATCH] Don't call [UIDevice currentDevice] in +load

Summary: sysctl should be faster.

Reviewed By: timonus

Differential Revision: D13981833

fbshipit-source-id: ae7a67d4eb69595441a4a66e0ef0a271762f77ce
---
 Source/IGListAdapter.m                           |  3 ++-
 Source/Internal/IGSystemVersion.h                |  8 ++++++++
 Source/Internal/IGSystemVersion.m                | 16 ++++++++++++++++
 ...ICollectionViewLayout+InteractiveReordering.m |  3 ++-
 4 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 Source/Internal/IGSystemVersion.h
 create mode 100644 Source/Internal/IGSystemVersion.m

diff --git a/Source/IGListAdapter.m b/Source/IGListAdapter.m
index d06c1bcd..5c0e1645 100644
--- a/Source/IGListAdapter.m
+++ b/Source/IGListAdapter.m
@@ -10,6 +10,7 @@
 #import <IGListKit/IGListAssert.h>
 #import <IGListKit/IGListAdapterUpdater.h>
 #import <IGListKit/IGListSupplementaryViewSource.h>
+#import <IGListKit/IGSystemVersion.h>
 
 #import "IGListSectionControllerInternal.h"
 #import "IGListDebugger.h"
@@ -26,7 +27,7 @@
 
 - (void)dealloc {
     // on iOS 9 setting the dataSource has side effects that can invalidate the layout and seg fault
-    if ([[[UIDevice currentDevice] systemVersion] floatValue] < 9.0) {
+    if (!IGSystemVersionIsIOS9OrNewer()) {
         // properties are assign for <iOS 9
         _collectionView.dataSource = nil;
         _collectionView.delegate = nil;
diff --git a/Source/Internal/IGSystemVersion.h b/Source/Internal/IGSystemVersion.h
new file mode 100644
index 00000000..5d94dc69
--- /dev/null
+++ b/Source/Internal/IGSystemVersion.h
@@ -0,0 +1,8 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+bool IGSystemVersionIsIOS9OrNewer(void);
diff --git a/Source/Internal/IGSystemVersion.m b/Source/Internal/IGSystemVersion.m
new file mode 100644
index 00000000..45b33463
--- /dev/null
+++ b/Source/Internal/IGSystemVersion.m
@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import "IGSystemVersion.h"
+
+bool IGSystemVersionIsIOS9OrNewer(void) {
+  if (@available(iOS 9.0, *)) {
+    return true;
+  } else {
+    return false;
+  }
+}
diff --git a/Source/Internal/UICollectionViewLayout+InteractiveReordering.m b/Source/Internal/UICollectionViewLayout+InteractiveReordering.m
index bfd473e2..1f2239ba 100644
--- a/Source/Internal/UICollectionViewLayout+InteractiveReordering.m
+++ b/Source/Internal/UICollectionViewLayout+InteractiveReordering.m
@@ -11,6 +11,7 @@
 #import <IGListKit/IGListAdapterInternal.h>
 #import <IGListKit/IGListAssert.h>
 #import <IGListKit/IGListSectionController.h>
+#import <IGListKit/IGSystemVersion.h>
 
 #import <objc/runtime.h>
 
@@ -23,7 +24,7 @@ static void * kIGListAdapterKey = &kIGListAdapterKey;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
         // interactive reordering does not exist prior to iOS 9
-        if ([[[UIDevice currentDevice] systemVersion] floatValue] < 9.0) {
+        if (!IGSystemVersionIsIOS9OrNewer()) {
             return;
         }