From b94dfac326be46cca0a0e019d132cb726c138a9e Mon Sep 17 00:00:00 2001
From: Alexandre Lissy <lissyx+mozillians@lissyx.dyndns.org>
Date: Mon, 12 Jan 2026 10:02:48 +0100
Subject: [PATCH] Enterprise: Check -felt for profile selection only on startup

Doing it in SelectStartupProfile() was somehow hitting race condition
leading to a segfault while running some tests, the stack including
XPCOM version of it.
---
 toolkit/profile/nsToolkitProfileService.cpp | 34 ---------------------
 toolkit/xre/nsAppRunner.cpp                 | 34 +++++++++++++++++++++
 2 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/toolkit/profile/nsToolkitProfileService.cpp b/toolkit/profile/nsToolkitProfileService.cpp
index 9254698f71ad..94e872caee66 100644
--- a/toolkit/profile/nsToolkitProfileService.cpp
+++ b/toolkit/profile/nsToolkitProfileService.cpp
@@ -41,10 +41,6 @@
 #  include "mozilla/WidgetUtilsGtk.h"
 #endif
 
-#if defined(MOZ_ENTERPRISE)
-#  include "mozilla/browser/extensions/felt/felt.h"
-#endif
-
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsNetCID.h"
@@ -1560,36 +1556,6 @@ nsresult nsToolkitProfileService::SelectStartupProfile(
     return NS_OK;
   }
 
-#if defined(MOZ_ENTERPRISE)
-  auto forcedProfile = geckoargs::sProfile.IsPresent(gArgc, gArgv);
-  if (is_felt_ui() && !forcedProfile) {
-    nsCOMPtr<nsIFile> file;
-    MOZ_TRY(
-        GetSpecialSystemDirectory(OS_TemporaryDirectory, getter_AddRefs(file)));
-    MOZ_TRY(file->AppendNative("felt"_ns));
-
-    bool exists = false;
-    MOZ_TRY(file->Exists(&exists));
-
-    if (!exists) {
-      // Create a unique profile directory.  This can fail if there are too many
-      // (thousands) of existing directories, which is unlikely to happen.
-      MOZ_TRY(file->CreateUnique(nsIFile::DIRECTORY_TYPE, 0700));
-    }
-
-    nsCOMPtr<nsIFile> localDir = file;
-    file.forget(aRootDir);
-    localDir.forget(aLocalDir);
-    // Background tasks never use profiles known to the profile service.
-    *aProfile = nullptr;
-
-    // consume -profile
-    (void)geckoargs::sProfile.Get(gArgc, gArgv);
-
-    return NS_OK;
-  }
-#endif
-
   // Check the -profile command line argument. It accepts a single argument that
   // gives the path to use for the profile.
   ArgResult ar = CheckArg(*aArgc, aArgv, "profile", &arg);
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index 352570e1f4a2..550f90cce5d5 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -46,6 +46,7 @@
 
 #if defined(MOZ_ENTERPRISE)
 #  include "mozilla/browser/extensions/felt/felt.h"
+#  include "SpecialSystemDirectory.h"
 #endif
 
 #include "nsAppRunner.h"
@@ -3118,6 +3119,39 @@ static nsresult SelectProfile(nsToolkitProfileService* aProfileSvc,
     return ShowProfileManager(aProfileSvc, aNative);
   }
 
+#if defined(MOZ_ENTERPRISE)
+  {
+    auto forcedProfile = geckoargs::sProfile.IsPresent(gArgc, gArgv);
+    if (is_felt_ui() && !forcedProfile) {
+      nsCOMPtr<nsIFile> file;
+      MOZ_TRY(GetSpecialSystemDirectory(OS_TemporaryDirectory,
+                                        getter_AddRefs(file)));
+      MOZ_TRY(file->AppendNative("felt"_ns));
+
+      bool exists = false;
+      MOZ_TRY(file->Exists(&exists));
+
+      if (!exists) {
+        // Create a unique profile directory.  This can fail if there are too
+        // many (thousands) of existing directories, which is unlikely to
+        // happen.
+        MOZ_TRY(file->CreateUnique(nsIFile::DIRECTORY_TYPE, 0700));
+      }
+
+      nsCOMPtr<nsIFile> localDir = file;
+      file.forget(aRootDir);
+      localDir.forget(aLocalDir);
+      // Background tasks never use profiles known to the profile service.
+      *aProfile = nullptr;
+
+      // consume -profile
+      (void)geckoargs::sProfile.Get(gArgc, gArgv);
+
+      return NS_OK;
+    }
+  }
+#endif
+
   // Ask the profile manager to select the profile directories to use.
   bool didCreate = false;
   rv = aProfileSvc->SelectStartupProfile(&gArgc, gArgv, gDoProfileReset,