diff --git a/layout/base/nsCSSRendering.cpp b/layout/base/nsCSSRendering.cpp
index aa8aff6ae..06ea7c2c1 100644
--- a/layout/base/nsCSSRendering.cpp
+++ b/layout/base/nsCSSRendering.cpp
@@ -17,6 +17,7 @@
 #include "mozilla/HashFunctions.h"
 #include "mozilla/MathAlgorithms.h"
 
+#include "nsISVGChildFrame.h"
 #include "nsStyleConsts.h"
 #include "nsPresContext.h"
 #include "nsIFrame.h"
@@ -4806,8 +4807,13 @@ nsImageRenderer::PrepareImage()
       mImageElementSurface =
         nsLayoutUtils::SurfaceFromElement(property->GetReferencedElement());
       if (!mImageElementSurface.GetSourceSurface()) {
-        mPaintServerFrame = property->GetReferencedFrame();
-        if (!mPaintServerFrame) {
+        nsIFrame* paintServerFrame = property->GetReferencedFrame();
+        // If there's no referenced frame, or the referenced frame is
+        // non-displayable SVG, then we have nothing valid to paint.
+        if (!paintServerFrame ||
+            (paintServerFrame->IsFrameOfType(nsIFrame::eSVG) &&
+             !paintServerFrame->IsFrameOfType(nsIFrame::eSVGPaintServer) &&
+             !static_cast<nsISVGChildFrame*>(do_QueryFrame(paintServerFrame)))) {
           mPrepareResult = DrawResult::BAD_IMAGE;
           return false;
         }
diff --git a/layout/svg/nsSVGIntegrationUtils.cpp b/layout/svg/nsSVGIntegrationUtils.cpp
index 0d88bede3..5dd556792 100644
--- a/layout/svg/nsSVGIntegrationUtils.cpp
+++ b/layout/svg/nsSVGIntegrationUtils.cpp
@@ -788,6 +788,15 @@ nsSVGIntegrationUtils::DrawableFromPaintServer(nsIFrame*         aFrame,
     return drawable.forget();
   }
 
+#if DEBUG
+  if (aFrame->IsFrameOfType(nsIFrame::eSVG) &&
+      !static_cast<nsISVGChildFrame*>(do_QueryFrame(aFrame))) {
+    MOZ_ASSERT_UNREACHABLE("We should prevent painting of unpaintable SVG "
+                           "before we get here");
+    return nullptr;
+  }
+#endif
+
   // We don't want to paint into a surface as long as we don't need to, so we
   // set up a drawing callback.
   RefPtr<gfxDrawingCallback> cb =
diff --git a/toolkit/components/prompts/src/nsPrompter.js b/toolkit/components/prompts/src/nsPrompter.js
index 2fa1b19d2..cb714d82a 100644
--- a/toolkit/components/prompts/src/nsPrompter.js
+++ b/toolkit/components/prompts/src/nsPrompter.js
@@ -371,6 +371,10 @@ function openTabPrompt(domWin, tabPrompt, args) {
                          .getInterface(Ci.nsIDOMWindowUtils);
     winUtils.enterModalState();
 
+    let frameMM = docShell.QueryInterface(Ci.nsIInterfaceRequestor)
+                          .getInterface(Ci.nsIContentFrameMessageManager);
+    frameMM.QueryInterface(Ci.nsIDOMEventTarget);
+
     // We provide a callback so the prompt can close itself. We don't want to
     // wait for this event loop to return... Otherwise the presence of other
     // prompts on the call stack would in this dialog appearing unresponsive
@@ -384,16 +388,25 @@ function openTabPrompt(domWin, tabPrompt, args) {
         if (newPrompt)
             tabPrompt.removePrompt(newPrompt);
 
-        domWin.removeEventListener("pagehide", pagehide);
+        frameMM.removeEventListener("pagehide", pagehide, true);
 
         winUtils.leaveModalState();
 
         PromptUtils.fireDialogEvent(domWin, "DOMModalDialogClosed");
     }
 
-    domWin.addEventListener("pagehide", pagehide);
-    function pagehide() {
-        domWin.removeEventListener("pagehide", pagehide);
+    frameMM.addEventListener("pagehide", pagehide, true);
+    function pagehide(e) {
+        // Check whether the event relates to our window or its ancestors
+        let window = domWin;
+        let eventWindow = e.target.defaultView;
+        while (window != eventWindow && window.parent != window) {
+          window = window.parent;
+        }
+        if (window != eventWindow) {
+          return;
+        }
+        frameMM.removeEventListener("pagehide", pagehide, true);
 
         if (newPrompt) {
             newPrompt.abortPrompt();
@@ -442,6 +455,9 @@ function openRemotePrompt(domWin, args, tabPrompt) {
     winUtils.enterModalState();
     let closed = false;
 
+    let frameMM = docShell.getInterface(Ci.nsIContentFrameMessageManager);
+    frameMM.QueryInterface(Ci.nsIDOMEventTarget);
+
     // It should be hard or impossible to cause a window to create multiple
     // prompts, but just in case, give our prompt an ID.
     let id = "id" + Cc["@mozilla.org/uuid-generator;1"]
@@ -453,7 +469,7 @@ function openRemotePrompt(domWin, args, tabPrompt) {
         }
 
         messageManager.removeMessageListener("Prompt:Close", listener);
-        domWin.removeEventListener("pagehide", pagehide);
+        frameMM.removeEventListener("pagehide", pagehide, true);
 
         winUtils.leaveModalState();
         PromptUtils.fireDialogEvent(domWin, "DOMModalDialogClosed");
@@ -470,9 +486,18 @@ function openRemotePrompt(domWin, args, tabPrompt) {
         closed = true;
     });
 
-    domWin.addEventListener("pagehide", pagehide);
-    function pagehide() {
-        domWin.removeEventListener("pagehide", pagehide);
+    frameMM.addEventListener("pagehide", pagehide, true);
+    function pagehide(e) {
+        // Check whether the event relates to our window or its ancestors
+        let window = domWin;
+        let eventWindow = e.target.defaultView;
+        while (window != eventWindow && window.parent != window) {
+          window = window.parent;
+        }
+        if (window != eventWindow) {
+          return;
+        }
+        frameMM.removeEventListener("pagehide", pagehide, true);
         messageManager.sendAsyncMessage("Prompt:ForceClose", { _remoteId: id });
     }