From 0df4377cec656df8af92ea20079cd920c48fdda9 Mon Sep 17 00:00:00 2001
From: Dave Townsend <dtownsend@oxymoronical.com>
Date: Tue, 5 Jul 2022 14:49:53 +0000
Subject: [PATCH] Bug 1778082: Ensure nsToolkitProfileService is a singleton
 regardless of how it is accessed. r=kmag

Differential Revision: https://phabricator.services.mozilla.com/D151020
---
 toolkit/profile/nsToolkitProfileService.cpp | 20 ++++++++++----------
 toolkit/profile/nsToolkitProfileService.h   |  7 ++++---
 toolkit/xre/components.conf                 |  3 ++-
 toolkit/xre/nsAppRunner.cpp                 |  9 ++-------
 toolkit/xre/nsAppRunner.h                   |  2 --
 5 files changed, 18 insertions(+), 23 deletions(-)

diff --git a/toolkit/profile/nsToolkitProfileService.cpp b/toolkit/profile/nsToolkitProfileService.cpp
index b788d383c201..156960935c8d 100644
--- a/toolkit/profile/nsToolkitProfileService.cpp
+++ b/toolkit/profile/nsToolkitProfileService.cpp
@@ -497,7 +497,6 @@ nsToolkitProfileService::nsToolkitProfileService()
 #ifdef MOZ_DEV_EDITION
   mUseDevEditionProfile = true;
 #endif
-  gService = this;
 }
 
 nsToolkitProfileService::~nsToolkitProfileService() {
@@ -2071,17 +2070,18 @@ nsToolkitProfileService::Flush() {
   return NS_OK;
 }
 
-nsresult NS_NewToolkitProfileService(nsToolkitProfileService** aResult) {
-  nsToolkitProfileService* profileService = new nsToolkitProfileService();
-  nsresult rv = profileService->Init();
-  if (NS_FAILED(rv)) {
-    NS_ERROR("nsToolkitProfileService::Init failed!");
-    delete profileService;
-    return rv;
+already_AddRefed<nsToolkitProfileService> NS_GetToolkitProfileService() {
+  if (!nsToolkitProfileService::gService) {
+    nsToolkitProfileService::gService = new nsToolkitProfileService();
+    nsresult rv = nsToolkitProfileService::gService->Init();
+    if (NS_FAILED(rv)) {
+      NS_ERROR("nsToolkitProfileService::Init failed!");
+      delete nsToolkitProfileService::gService;
+      return nullptr;
+    }
   }
 
-  NS_ADDREF(*aResult = profileService);
-  return NS_OK;
+  return do_AddRef(nsToolkitProfileService::gService);
 }
 
 nsresult XRE_GetFileFromPath(const char* aPath, nsIFile** aResult) {
diff --git a/toolkit/profile/nsToolkitProfileService.h b/toolkit/profile/nsToolkitProfileService.h
index 97ef74855956..dea1af012440 100644
--- a/toolkit/profile/nsToolkitProfileService.h
+++ b/toolkit/profile/nsToolkitProfileService.h
@@ -80,9 +80,8 @@ class nsToolkitProfileService final : public nsIToolkitProfileService {
 
  private:
   friend class nsToolkitProfile;
-  friend nsresult NS_NewToolkitProfileService(nsToolkitProfileService**);
-  friend nsresult mozilla::xpcom::CreateInstanceImpl(
-      mozilla::xpcom::ModuleID aID, const nsIID& aIID, void** aResult);
+  friend already_AddRefed<nsToolkitProfileService>
+  NS_GetToolkitProfileService();
 
   nsToolkitProfileService();
   ~nsToolkitProfileService();
@@ -173,4 +172,6 @@ class nsToolkitProfileService final : public nsIToolkitProfileService {
   };
 };
 
+already_AddRefed<nsToolkitProfileService> NS_GetToolkitProfileService();
+
 #endif
diff --git a/toolkit/xre/components.conf b/toolkit/xre/components.conf
index 5f23dc4a13b0..626fa65e9a07 100644
--- a/toolkit/xre/components.conf
+++ b/toolkit/xre/components.conf
@@ -62,8 +62,9 @@ Classes = [
     {
         'cid': '{5f5e59ce-27bc-47eb-9d1f-b09ca9049836}',
         'contract_ids': ['@mozilla.org/toolkit/profile-service;1'],
+        'singleton': True,
+        'constructor': 'NS_GetToolkitProfileService',
         'type': 'nsToolkitProfileService',
-        'init_method': 'Init',
         'headers': ['/toolkit/profile/nsToolkitProfileService.h'],
     },
 ]
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index 47ddc99374e5..45d81edd2fcb 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -4892,13 +4892,8 @@ int XREMain::XRE_mainStartup(bool* aExitFlag) {
   }
 #endif
 
-  rv = NS_NewToolkitProfileService(getter_AddRefs(mProfileSvc));
-  if (rv == NS_ERROR_FILE_ACCESS_DENIED) {
-    PR_fprintf(PR_STDERR,
-               "Error: Access was denied while trying to open files in "
-               "your profile directory.\n");
-  }
-  if (NS_FAILED(rv)) {
+  mProfileSvc = NS_GetToolkitProfileService();
+  if (!mProfileSvc) {
     // We failed to choose or create profile - notify user and quit
     ProfileMissingDialog(mNativeApp);
     return 1;
diff --git a/toolkit/xre/nsAppRunner.h b/toolkit/xre/nsAppRunner.h
index a09d665e3aa0..e364f81a9f74 100644
--- a/toolkit/xre/nsAppRunner.h
+++ b/toolkit/xre/nsAppRunner.h
@@ -78,8 +78,6 @@ int32_t CompareCompatVersions(const nsACString& aOldCompatVersion,
 nsresult NS_CreateNativeAppSupport(nsINativeAppSupport** aResult);
 already_AddRefed<nsINativeAppSupport> NS_GetNativeAppSupport();
 
-nsresult NS_NewToolkitProfileService(nsIToolkitProfileService** aResult);
-
 /**
  * Try to acquire exclusive access to the specified profile directory.
  *