diff --git a/dom/base/nsFrameLoader.cpp b/dom/base/nsFrameLoader.cpp
index 773552c1f50a..a95babb1bdeb 100644
--- a/dom/base/nsFrameLoader.cpp
+++ b/dom/base/nsFrameLoader.cpp
@@ -47,6 +47,7 @@
 #include "nsPIWindowRoot.h"
 #include "nsLayoutUtils.h"
 #include "nsView.h"
+#include "nsViewManager.h"
 #include "nsBaseWidget.h"
 #include "nsQueryObject.h"
 #include "ReferrerInfo.h"
@@ -992,6 +993,14 @@ bool nsFrameLoader::Show(nsSubDocumentFrame* frame) {
   ds->SetScrollbarPreference(GetScrollbarPreference(mOwnerContent));
   const bool marginsChanged =
       ds->UpdateFrameMargins(GetMarginAttributes(mOwnerContent));
+
+  nsView* view = frame->EnsureInnerView();
+  if (!view) {
+    return false;
+  }
+
+  
+  
   if (PresShell* presShell = ds->GetPresShell()) {
     
     if (marginsChanged) {
@@ -1000,11 +1009,21 @@ bool nsFrameLoader::Show(nsSubDocumentFrame* frame) {
                                     NS_FRAME_IS_DIRTY);
       }
     }
-    return true;
-  }
+    nsView* childView = presShell->GetViewManager()->GetRootView();
+    MOZ_DIAGNOSTIC_ASSERT(childView);
+    if (childView->GetParent() == view) {
+      
+      
+      return true;
+    }
 
-  nsView* view = frame->EnsureInnerView();
-  if (!view) return false;
+    
+    
+    MOZ_DIAGNOSTIC_ASSERT(!view->GetFirstChild());
+    MOZ_DIAGNOSTIC_ASSERT(!childView->GetParent(), "Stale view?");
+    nsSubDocumentFrame::InsertViewsInReverseOrder(childView, view);
+    nsSubDocumentFrame::EndSwapDocShellsForViews(view->GetFirstChild());
+  }
 
   RefPtr<nsDocShell> baseWindow = GetDocShell();
   baseWindow->InitWindow(nullptr, view->GetWidget(), 0, 0, size.width,
@@ -1016,6 +1035,9 @@ bool nsFrameLoader::Show(nsSubDocumentFrame* frame) {
   
   
   
+  
+  
+  
   if (RefPtr<PresShell> presShell = GetDocShell()->GetPresShell()) {
     Document* doc = presShell->GetDocument();
     nsHTMLDocument* htmlDoc =
diff --git a/layout/generic/nsSubDocumentFrame.cpp b/layout/generic/nsSubDocumentFrame.cpp
index 80e198f726d1..954ab78f69b5 100644
--- a/layout/generic/nsSubDocumentFrame.cpp
+++ b/layout/generic/nsSubDocumentFrame.cpp
@@ -116,10 +116,6 @@ class AsyncFrameInit : public Runnable {
   WeakFrame mFrame;
 };
 
-static void InsertViewsInReverseOrder(nsView* aSibling, nsView* aParent);
-
-static void EndSwapDocShellsForViews(nsView* aView);
-
 void nsSubDocumentFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
                               nsIFrame* aPrevInFlow) {
   MOZ_ASSERT(aContent);
@@ -148,8 +144,8 @@ void nsSubDocumentFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
     nsView* detachedView = detachedFrame ? detachedFrame->GetView() : nullptr;
     if (detachedView) {
       
-      ::InsertViewsInReverseOrder(detachedView, mInnerView);
-      ::EndSwapDocShellsForViews(mInnerView->GetFirstChild());
+      InsertViewsInReverseOrder(detachedView, mInnerView);
+      EndSwapDocShellsForViews(mInnerView->GetFirstChild());
     } else if (hadFrame) {
       
       frameloader->Hide();
@@ -921,7 +917,7 @@ class nsHideViewer final : public Runnable {
     mFrameLoader->SetDetachedSubdocFrame(nullptr);
 
     nsSubDocumentFrame* frame = do_QueryFrame(mFrameElement->GetPrimaryFrame());
-    if (!frame) {
+    if (!frame || frame->FrameLoader() != mFrameLoader) {
       PropagateIsUnderHiddenEmbedderElement(mFrameLoader, true);
       if (mHideViewerIfFrameless) {
         
@@ -1080,7 +1076,9 @@ static nsView* BeginSwapDocShellsForViews(nsView* aSibling) {
   return removedViews;
 }
 
-static void InsertViewsInReverseOrder(nsView* aSibling, nsView* aParent) {
+
+void nsSubDocumentFrame::InsertViewsInReverseOrder(nsView* aSibling,
+                                                   nsView* aParent) {
   MOZ_ASSERT(aParent, "null view");
   MOZ_ASSERT(!aParent->GetFirstChild(), "inserting into non-empty list");
 
@@ -1115,8 +1113,8 @@ nsresult nsSubDocumentFrame::BeginSwapDocShells(nsIFrame* aOther) {
     nsView* otherSubdocViews = other->mInnerView->GetFirstChild();
     nsView* otherRemovedViews = ::BeginSwapDocShellsForViews(otherSubdocViews);
 
-    ::InsertViewsInReverseOrder(ourRemovedViews, other->mInnerView);
-    ::InsertViewsInReverseOrder(otherRemovedViews, mInnerView);
+    InsertViewsInReverseOrder(ourRemovedViews, other->mInnerView);
+    InsertViewsInReverseOrder(otherRemovedViews, mInnerView);
   }
   mFrameLoader.swap(other->mFrameLoader);
   return NS_OK;
@@ -1147,7 +1145,8 @@ static CallState EndSwapDocShellsForDocument(Document& aDocument) {
   return CallState::Continue;
 }
 
-static void EndSwapDocShellsForViews(nsView* aSibling) {
+
+void nsSubDocumentFrame::EndSwapDocShellsForViews(nsView* aSibling) {
   for (; aSibling; aSibling = aSibling->GetNextSibling()) {
     if (Document* doc = ::GetDocumentFromView(aSibling)) {
       ::EndSwapDocShellsForDocument(*doc);
@@ -1178,10 +1177,10 @@ void nsSubDocumentFrame::EndSwapDocShells(nsIFrame* aOther) {
   AutoWeakFrame weakOther(aOther);
 
   if (mInnerView) {
-    ::EndSwapDocShellsForViews(mInnerView->GetFirstChild());
+    EndSwapDocShellsForViews(mInnerView->GetFirstChild());
   }
   if (other->mInnerView) {
-    ::EndSwapDocShellsForViews(other->mInnerView->GetFirstChild());
+    EndSwapDocShellsForViews(other->mInnerView->GetFirstChild());
   }
 
   
diff --git a/layout/generic/nsSubDocumentFrame.h b/layout/generic/nsSubDocumentFrame.h
index 4dc28e88ed44..886e4f1656dd 100644
--- a/layout/generic/nsSubDocumentFrame.h
+++ b/layout/generic/nsSubDocumentFrame.h
@@ -96,6 +96,10 @@ class nsSubDocumentFrame final : public nsAtomicContainerFrame,
   nsIDocShell* GetDocShell() const;
   nsresult BeginSwapDocShells(nsIFrame* aOther);
   void EndSwapDocShells(nsIFrame* aOther);
+
+  static void InsertViewsInReverseOrder(nsView* aSibling, nsView* aParent);
+  static void EndSwapDocShellsForViews(nsView* aView);
+
   nsView* EnsureInnerView();
   nsPoint GetExtraOffset() const;
   nsIFrame* GetSubdocumentRootFrame();
diff --git a/layout/reftests/bugs/1624118-ref.html b/layout/reftests/bugs/1624118-ref.html
new file mode 100644
index 000000000000..3c10ed7406fb
--- /dev/null
+++ b/layout/reftests/bugs/1624118-ref.html
@@ -0,0 +1,2 @@
+<!doctype html>
+<object type="image/svg+xml" data="243519-8.svg"></object>
diff --git a/layout/reftests/bugs/1624118.html b/layout/reftests/bugs/1624118.html
new file mode 100644
index 000000000000..a6b4a1465af4
--- /dev/null
+++ b/layout/reftests/bugs/1624118.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<html class="reftest-wait">
+<script>
+  let loadedOnce = false;
+  function objectLoaded() {
+    let firstTime = !loadedOnce;
+    loadedOnce = true;
+    let object = document.querySelector("object");
+    if (!firstTime) {
+      document.documentElement.className = "";
+      return;
+    }
+    // The svgs used in this test are arbitrary, but should obviously match the
+    // reference and should be different from each other.
+    object.data = "243519-8.svg";
+  }
+</script>
+<object onload="objectLoaded()" type="image/svg+xml" data="315920-20.svg"></object>
diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index 7630cb9d6d93..0e6c7d1bc7e4 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -2074,6 +2074,7 @@ skip-if(!OSX) != 1608124-2.html 1608124-2-notref.html
 fuzzy(0-145,0-48536) == 1614788-1.svg 1614788-1-ref.svg # large fuzz necesary to test bug: 239,202824 is how much it differs when bug exists
 == blob-fallback-clip.html blob-fallback-clip-ref.html
 fuzzy-if(OSX,0-42,0-4) fuzzy-if(winWidget,249-249,999-999) == 1617515-1.html 1617515-1-ref.html
+== 1624118.html 1624118-ref.html
 fuzzy(0-2,0-21184) == 1626259-1.html 1626259-1-ref.html
 fuzzy(0-2,0-21184) == 1626259-2.html 1626259-2-ref.html
 != 1642583-1.html 1642583-1-ref.html