From fd59d6a4ddbb019bae9ba1850dd541f77a34e172 Mon Sep 17 00:00:00 2001
From: Edgar Chen <echen@mozilla.com>
Date: Fri, 14 Mar 2025 19:55:01 +0000
Subject: [PATCH] Bug 1952343 - [about:memory] Wait for document to regain
 focus before reopening the file picker; r=mccr8

Differential Revision: https://phabricator.services.mozilla.com/D241441
---
 .../aboutmemory/content/aboutMemory.js        | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/toolkit/components/aboutmemory/content/aboutMemory.js b/toolkit/components/aboutmemory/content/aboutMemory.js
index 46a4990a5224..883a85e30361 100644
--- a/toolkit/components/aboutmemory/content/aboutMemory.js
+++ b/toolkit/components/aboutmemory/content/aboutMemory.js
@@ -327,13 +327,24 @@ window.onload = function () {
         // onchange handler to be re-called without having to go via the file
         // picker.
         if (!aElem.skipClick) {
+          // Attempts to reopen the picker immediately might fail because the
+          // focus may not have switched back on some platform, so explicitly
+          //  wait for focus here.
+          if (!this.ownerDocument.hasFocus()) {
+            let input = this;
+            this.ownerDocument.addEventListener("focus", (e) => {
+              input.click();
+            }, { once: true });
+            return;
+          }
           this.click();
         }
-      } else {
-        let filename1 = this.filename1;
-        delete this.filename1;
-        updateAboutMemoryFromTwoFiles(filename1, file.mozFullPath);
+        return;
       }
+
+      let filename1 = this.filename1;
+      delete this.filename1;
+      updateAboutMemoryFromTwoFiles(filename1, file.mozFullPath);
     }
   );