From e208782cd3644510aeedee12aa27abef069aecbd Mon Sep 17 00:00:00 2001
From: Olli Pettay <Olli.Pettay@helsinki.fi>
Date: Fri, 20 Dec 2024 22:12:06 +0000
Subject: [PATCH] Bug 1778923, set pointer-events: none; on xul:browser when
 select popup is open, r=edgar,emilio,desktop-theme-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D232557
---
 dom/events/EventStateManager.cpp    | 15 ++++++++++++++-
 toolkit/actors/SelectParent.sys.mjs |  6 +++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/dom/events/EventStateManager.cpp b/dom/events/EventStateManager.cpp
index 2f453aba9b51..2b0634bb03b0 100644
--- a/dom/events/EventStateManager.cpp
+++ b/dom/events/EventStateManager.cpp
@@ -1923,7 +1923,20 @@ static void DispatchCrossProcessMouseExitEvents(WidgetMouseEvent* aMouseEvent,
     mouseExitEvent->mExitFrom =
         Some(aIsReallyExit ? WidgetMouseEvent::ePuppet
                            : WidgetMouseEvent::ePuppetParentToPuppetChild);
-    aRemoteTarget->SendRealMouseEvent(*mouseExitEvent);
+
+    auto ContentReactsToPointerEvents = [](BrowserParent* aRemoteTarget) {
+      if (Element* owner = aRemoteTarget->GetOwnerElement()) {
+        if (nsSubDocumentFrame* subDocFrame =
+                do_QueryFrame(owner->GetPrimaryFrame())) {
+          return subDocFrame->ContentReactsToPointerEvents();
+        }
+      }
+      return true;
+    };
+
+    if (ContentReactsToPointerEvents(aRemoteTarget)) {
+      aRemoteTarget->SendRealMouseEvent(*mouseExitEvent);
+    }
 
     aRemoteTarget = GetBrowserParentAncestor(aRemoteTarget);
   }
diff --git a/toolkit/actors/SelectParent.sys.mjs b/toolkit/actors/SelectParent.sys.mjs
index 2db3e3250c0d..3e1d4b73b3d8 100644
--- a/toolkit/actors/SelectParent.sys.mjs
+++ b/toolkit/actors/SelectParent.sys.mjs
@@ -319,6 +319,7 @@ export var SelectParentHelper = {
     let win = menulist.ownerGlobal;
     if (browser) {
       browser.constrainPopup(menupopup);
+      browser.style.pointerEvents = "none";
     } else {
       menupopup.setConstraintRect(new win.DOMRect(0, 0, 0, 0));
     }
@@ -405,7 +406,10 @@ export var SelectParentHelper = {
         let popup = event.target;
         this._unregisterListeners(popup);
         popup.parentNode.hidden = true;
-        this._currentBrowser = null;
+        if (this._currentBrowser) {
+          this._currentBrowser.style.pointerEvents = "";
+          this._currentBrowser = null;
+        }
         this._currentMenulist = null;
         this._selectRect = null;
         this._currentZoom = 1;