From 668296cf5d07b4bb7ac6b4227e47097c7dff7ace Mon Sep 17 00:00:00 2001
From: Job Bautista <jobbautista9@protonmail.com>
Date: Wed, 10 Dec 2025 11:08:59 +0800
Subject: [PATCH] Issue #2861 - Part 2 Follow-up: nsIPluginHost.isPluginOOP
 should not always return true.

Actually restore the method as it was when it was added in Mozilla bug 1178896.
---
 dom/plugins/base/nsPluginHost.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dom/plugins/base/nsPluginHost.cpp b/dom/plugins/base/nsPluginHost.cpp
index 0b2a0c4c08..e6d7accf65 100644
--- a/dom/plugins/base/nsPluginHost.cpp
+++ b/dom/plugins/base/nsPluginHost.cpp
@@ -1063,7 +1063,11 @@ NS_IMETHODIMP
 nsPluginHost::IsPluginOOP(const nsACString& aMimeType,
                           bool* aResult)
 {
-  *aResult = true;
+  nsPluginTag* tag = FindNativePluginForType(aMimeType, true);
+  if (!tag) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  *aResult = nsNPAPIPlugin::RunPluginOOP(tag);
   return NS_OK;
 }