Respond to CR.

Signal/src/ViewControllers/AppSettings/OWSLinkedDevicesTableViewController.m

@@ -46,13 +46,7 @@ int const OWSLinkedDevicesTableViewControllerSectionAddDevice = 1;
     self.tableView.rowHeight = UITableViewAutomaticDimension;
     self.tableView.estimatedRowHeight = 70;
 
-    // Fix a bug that only affects iOS 11.0.x and 11.1.x.
-    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 0) && !SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 2)) {
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wpartial-availability"
-        self.tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
-#pragma clang diagnostic pop
-    }
+    [self.tableView applyScrollViewInsetsFix];
 
     self.dbConnection = [[OWSPrimaryStorage sharedManager] newDatabaseConnection];
     [self.dbConnection beginLongLivedReadTransaction];

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -521,13 +521,7 @@ typedef enum : NSUInteger {
     [self.collectionView autoPinWidthToSuperview];
     [self.collectionView autoPinToTopLayoutGuideOfViewController:self withInset:0];
 
-    // Fix a bug that only affects iOS 11.0.x and 11.1.x.
-    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 0) && !SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 2)) {
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wpartial-availability"
-        self.collectionView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
-#pragma clang diagnostic pop
-    }
+    [self.collectionView applyScrollViewInsetsFix];
 
     _inputToolbar = [ConversationInputToolbar new];
     self.inputToolbar.inputToolbarDelegate = self;

Signal/src/ViewControllers/MediaDetailViewController.m

@@ -216,7 +216,7 @@ NS_ASSUME_NONNULL_BEGIN
     scrollView.decelerationRate = UIScrollViewDecelerationRateFast;
 
     if (@available(iOS 11.0, *)) {
-        scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
+        [scrollView contentInsetAdjustmentBehavior];
     } else {
         self.automaticallyAdjustsScrollViewInsets = NO;
     }

Signal/src/ViewControllers/MessageDetailViewController.swift

@@ -146,6 +146,8 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
                 UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
             ]
         } else {
+            scrollView.applyInsetsFix()
+
             scrollView.autoPinEdge(toSuperviewEdge: .bottom)
         }
 

SignalMessaging/ViewControllers/OWSTableViewController.m

@@ -452,13 +452,9 @@ NSString *const kOWSTableCellIdentifier = @"kOWSTableCellIdentifier";
     self.tableView.delegate = self;
     self.tableView.dataSource = self;
     self.tableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
-    // Fix a bug that only affects iOS 11.0.x and 11.1.x.
-    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 0) && !SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 2)) {
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wpartial-availability"
-        self.tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
-#pragma clang diagnostic pop
-    }
+
+    [self.tableView applyScrollViewInsetsFix];
+
     [self.view addSubview:self.tableView];
     [self.tableView autoPinWidthToSuperview];
     [self.tableView autoPinToTopLayoutGuideOfViewController:self withInset:0];

SignalMessaging/categories/UIView+OWS.h

@@ -125,6 +125,14 @@ CGFloat ScaleFromIPhone5(CGFloat iPhone5Value);
 
 @end
 
+#pragma mark -
+
+@interface UIScrollView (OWS)
+
+- (void)applyScrollViewInsetsFix;
+
+@end
+
 #pragma mark - Macros
 
 CG_INLINE CGSize CGSizeCeil(CGSize size)

SignalMessaging/categories/UIView+OWS.m

@@ -487,4 +487,21 @@ CGFloat ScaleFromIPhone5(CGFloat iPhone5Value)
 
 @end
 
+#pragma mark -
+
+@implementation UIScrollView (OWS)
+
+- (void)applyScrollViewInsetsFix
+{
+    // Fix a bug that only affects iOS 11.0.x and 11.1.x.
+    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 0) && !SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(11, 2)) {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wpartial-availability"
+        self.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
+#pragma clang diagnostic pop
+    }
+}
+
+@end
+
 NS_ASSUME_NONNULL_END