Fix pager node for interface coalescing

Source/ASDisplayNode+Subclasses.h

@@ -362,6 +362,12 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)didExitHierarchy ASDISPLAYNODE_REQUIRES_SUPER;
 
+/**
+ * Called just after the view is added to a window.
+ * Note: this may be called multiple times during view controller transitions. To overcome this: use didEnterVisibleState or it's equavalents.
+ */
+- (void)didEnterHierarchy ASDISPLAYNODE_REQUIRES_SUPER;
+
 /**
  * @abstract Whether the view or layer of this display node is currently in a window
  */

Source/ASDisplayNode.mm

@@ -2876,6 +2876,8 @@ - (void)__enterHierarchy
   }
 
   __instanceLock__.unlock();
+
+  [self didEnterHierarchy];
 }
 
 - (void)__exitHierarchy
@@ -2996,6 +2998,14 @@ - (void)willEnterHierarchy
   }
 }
 
+- (void)didEnterHierarchy {
+  ASDisplayNodeAssertMainThread();
+  ASDisplayNodeAssert(!_flags.isEnteringHierarchy, @"You should never call -willEnterHierarchy directly. Appearance is automatically managed by ASDisplayNode");
+  ASDisplayNodeAssert(!_flags.isExitingHierarchy, @"ASDisplayNode inconsistency. __enterHierarchy and __exitHierarchy are mutually exclusive");
+  ASDisplayNodeAssert(_flags.isInHierarchy, @"ASDisplayNode inconsistency. __enterHierarchy and __exitHierarchy are mutually exclusive");
+  ASDisplayNodeAssertLockUnownedByCurrentThread(__instanceLock__);
+}
+
 - (void)didExitHierarchy
 {
   ASDisplayNodeAssertMainThread();

Source/ASPagerNode.m

@@ -221,14 +221,12 @@ - (void)proxyTargetHasDeallocated:(ASDelegateProxy *)proxy
   [self setDelegate:nil];
 }
 
-- (void)didEnterVisibleState
+- (void)didEnterHierarchy
 {
-	[super didEnterVisibleState];
+	[super didEnterHierarchy];
 
 	// Check that our view controller does not automatically set our content insets
-	// It would be better to have a -didEnterHierarchy hook to put this in, but
-	// such a hook doesn't currently exist, and in every use case I can imagine,
-	// the pager is not hosted inside a range-managed node.
+	// In every use case I can imagine, the pager is not hosted inside a range-managed node.
 	if (_allowsAutomaticInsetsAdjustment == NO) {
 		UIViewController *vc = [self.view asdk_associatedViewController];
 		if (vc.automaticallyAdjustsScrollViewInsets) {