diff --git a/build/moz.configure/bindgen.configure b/build/moz.configure/bindgen.configure
index 9c617a80aa49..b5ac417b25fe 100644
--- a/build/moz.configure/bindgen.configure
+++ b/build/moz.configure/bindgen.configure
@@ -320,8 +320,6 @@ def basic_bindgen_cflags(host, target, is_unix, compiler_info, android_cflags):
             'compiler': {
                 'msvc': {
                     'default': [
-                        # For compatibility with MSVC 2015
-                        '-fms-compatibility-version=19',
                         # To enable the builtin __builtin_offsetof so that CRT wouldn't
                         # use reinterpret_cast in offsetof() which is not allowed inside
                         # static_assert().
diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 198bc3cb0eec..bd10811a84ab 100755
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -619,13 +619,6 @@ def check_compiler(compiler, language, target):
         elif info.type == 'clang-cl' and info.language_version != cxx14_version:
             append_flag('-std=c++14')
 
-    # We force clang-cl to emulate Visual C++ 2017 version 15.8.4
-    msvc_version = '19.15.26726'
-    if info.type == 'clang-cl' and info.version != msvc_version:
-        # This flag is a direct clang-cl flag that doesn't need -Xclang,
-        # add it directly.
-        flags.append('-fms-compatibility-version=%s' % msvc_version)
-
     # Check compiler target
     # --------------------------------------------------------------------
     if not info.cpu or info.cpu != target.cpu:
diff --git a/dom/base/ChromeUtils.cpp b/dom/base/ChromeUtils.cpp
index 46f124a748e1..3d9c7abf264a 100644
--- a/dom/base/ChromeUtils.cpp
+++ b/dom/base/ChromeUtils.cpp
@@ -830,6 +830,11 @@ constexpr auto kSkipSelfHosted = JS::SavedFrameSelfHosted::Exclude;
   return duration.ToMilliseconds();
 }
 
+/* static */ void ChromeUtils::ResetLastExternalProtocolIframeAllowed(
+    GlobalObject& aGlobal) {
+  PopupBlocker::ResetLastExternalProtocolIframeAllowed();
+}
+
 /* static */ void ChromeUtils::RegisterWindowActor(
     const GlobalObject& aGlobal, const nsAString& aName,
     const WindowActorOptions& aOptions, ErrorResult& aRv) {
diff --git a/dom/base/ChromeUtils.h b/dom/base/ChromeUtils.h
index f112c425a7c5..7e16a9d1b899 100644
--- a/dom/base/ChromeUtils.h
+++ b/dom/base/ChromeUtils.h
@@ -180,6 +180,8 @@ class ChromeUtils {
 
   static double LastExternalProtocolIframeAllowed(GlobalObject& aGlobal);
 
+  static void ResetLastExternalProtocolIframeAllowed(GlobalObject& aGlobal);
+
   static void RegisterWindowActor(const GlobalObject& aGlobal,
                                   const nsAString& aName,
                                   const WindowActorOptions& aOptions,
diff --git a/dom/base/PopupBlocker.cpp b/dom/base/PopupBlocker.cpp
index 7a0bcfd3ed0e..ec8b9f695bb9 100644
--- a/dom/base/PopupBlocker.cpp
+++ b/dom/base/PopupBlocker.cpp
@@ -404,6 +404,10 @@ PopupBlocker::PopupControlState PopupBlocker::GetEventPopupControlState(
   return sLastAllowedExternalProtocolIFrameTimeStamp;
 }
 
+/* static */ void PopupBlocker::ResetLastExternalProtocolIframeAllowed() {
+  sLastAllowedExternalProtocolIFrameTimeStamp = TimeStamp();
+}
+
 }  // namespace dom
 }  // namespace mozilla
 
diff --git a/dom/base/PopupBlocker.h b/dom/base/PopupBlocker.h
index 1e7e486b35d5..4b410a3c770e 100644
--- a/dom/base/PopupBlocker.h
+++ b/dom/base/PopupBlocker.h
@@ -59,6 +59,9 @@ class PopupBlocker final {
   // Returns when the last external protocol iframe has been allowed.
   static TimeStamp WhenLastExternalProtocolIframeAllowed();
 
+  // Reset the last external protocol iframe timestamp.
+  static void ResetLastExternalProtocolIframeAllowed();
+
   static void Initialize();
   static void Shutdown();
 };
diff --git a/dom/chrome-webidl/ChromeUtils.webidl b/dom/chrome-webidl/ChromeUtils.webidl
index d31ae1ce1dc7..800fff2a6105 100644
--- a/dom/chrome-webidl/ChromeUtils.webidl
+++ b/dom/chrome-webidl/ChromeUtils.webidl
@@ -395,6 +395,12 @@ partial namespace ChromeUtils {
   [ChromeOnly]
   double lastExternalProtocolIframeAllowed();
 
+  /**
+   * For testing purpose we need to reset this value.
+   */
+  [ChromeOnly]
+  void resetLastExternalProtocolIframeAllowed();
+
   [ChromeOnly, Throws]
   void registerWindowActor(DOMString aName, WindowActorOptions aOptions);
 };
diff --git a/dom/html/test/test_external_protocol_iframe.html b/dom/html/test/test_external_protocol_iframe.html
index b2daf5283c92..858cc6bab118 100644
--- a/dom/html/test/test_external_protocol_iframe.html
+++ b/dom/html/test/test_external_protocol_iframe.html
@@ -10,6 +10,11 @@
   <div id='foo'><a href='#'>Click here to test this issue</a></div>
   <script>
 
+function test_initialize() {
+  ChromeUtils.resetLastExternalProtocolIframeAllowed();
+  next();
+}
+
 function test_noUserInteraction() {
   is(ChromeUtils.getPopupControlState(), "openAbused", "No user-interaction means: abuse state");
   ok(!ChromeUtils.isPopupTokenUnused(), "Popup token has not been used yet");
@@ -53,6 +58,7 @@ function test_userInteraction() {
 }
 
 let tests = [
+  test_initialize,
   test_noUserInteraction,
   test_userInteraction,
 ];
diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index 3f965376caad..52431719410f 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -16223,10 +16223,15 @@ nsresult QuotaClient::GetDatabaseFilenames(
       continue;
     }
 
-    // Skip Desktop Service Store (.DS_Store) files. These files are only used
-    // on Mac OS X, but the profile can be shared across different operating
-    // systems, so we check it on all platforms.
-    if (leafName.EqualsLiteral(DSSTORE_FILE_NAME)) {
+    // Skip OS metadata files. These files are only used in different platforms,
+    // but the profile can be shared across different operating systems, so we
+    // check it on all platforms.
+    if (QuotaManager::IsOSMetadata(leafName)) {
+      continue;
+    }
+
+    // Skip files starting with ".".
+    if (QuotaManager::IsDotFile(leafName)) {
       continue;
     }
 
@@ -16310,6 +16315,11 @@ nsresult QuotaClient::GetUsageForDirectoryInternal(nsIFile* aDirectory,
       continue;
     }
 
+    if (QuotaManager::IsOSMetadata(leafName) ||
+        QuotaManager::IsDotFile(leafName)) {
+      continue;
+    }
+
     // Journal files and sqlite-shm files don't count towards usage.
     if (StringEndsWith(leafName, journalSuffix) ||
         StringEndsWith(leafName, shmSuffix)) {
diff --git a/dom/quota/ActorsParent.cpp b/dom/quota/ActorsParent.cpp
index 62da8b8c924d..051cac551b3c 100644
--- a/dom/quota/ActorsParent.cpp
+++ b/dom/quota/ActorsParent.cpp
@@ -1267,8 +1267,12 @@ void AssertNoUnderflow(T aDest, U aArg) {
   MOZ_ASSERT(uint64_t(aDest) >= uint64_t(aArg));
 }
 
-bool IsOSMetadata(const nsAString& aFileName) {
-  return aFileName.EqualsLiteral(DSSTORE_FILE_NAME);
+inline bool IsDotFile(const nsAString& aFileName) {
+  return QuotaManager::IsDotFile(aFileName);
+}
+
+inline bool IsOSMetadata(const nsAString& aFileName) {
+  return QuotaManager::IsOSMetadata(aFileName);
 }
 
 bool IsOriginMetadata(const nsAString& aFileName) {
@@ -1668,7 +1672,8 @@ int64_t GetLastModifiedTime(nsIFile* aFile, bool aPersistent) {
           return rv;
         }
 
-        if (IsOriginMetadata(leafName) || IsTempMetadata(leafName)) {
+        if (IsOriginMetadata(leafName) || IsTempMetadata(leafName) ||
+            IsDotFile(leafName)) {
           return NS_OK;
         }
 
@@ -2869,6 +2874,19 @@ QuotaManager* QuotaManager::Get() {
 // static
 bool QuotaManager::IsShuttingDown() { return gShutdown; }
 
+// static
+bool QuotaManager::IsOSMetadata(const nsAString& aFileName) {
+  return aFileName.EqualsLiteral(DSSTORE_FILE_NAME) ||
+         aFileName.EqualsLiteral(DESKTOP_FILE_NAME) ||
+         aFileName.LowerCaseEqualsLiteral(DESKTOP_INI_FILE_NAME) ||
+         aFileName.EqualsLiteral(THUMBS_DB_FILE_NAME);
+}
+
+// static
+bool QuotaManager::IsDotFile(const nsAString& aFileName) {
+  return aFileName.First() == char16_t('.');
+}
+
 auto QuotaManager::CreateDirectoryLock(
     const Nullable<PersistenceType>& aPersistenceType, const nsACString& aGroup,
     const OriginScope& aOriginScope, const Nullable<Client::Type>& aClientType,
@@ -3763,7 +3781,7 @@ nsresult QuotaManager::InitializeRepository(PersistenceType aPersistenceType) {
         CONTINUE_IN_NIGHTLY_RETURN_IN_OTHERS(rv);
       }
 
-      if (IsOSMetadata(leafName)) {
+      if (IsOSMetadata(leafName) || IsDotFile(leafName)) {
         continue;
       }
 
@@ -3880,6 +3898,10 @@ nsresult QuotaManager::InitializeOrigin(PersistenceType aPersistenceType,
         continue;
       }
 
+      if (IsOSMetadata(leafName) || IsDotFile(leafName)) {
+        continue;
+      }
+
       UNKNOWN_FILE_WARNING(leafName);
       REPORT_TELEMETRY_INIT_ERR(kInternalError, Ori_UnexpectedFile);
       RECORD_IN_NIGHTLY(statusKeeper, NS_ERROR_UNEXPECTED);
@@ -6616,6 +6638,10 @@ nsresult QuotaUsageRequestBase::GetUsageForOrigin(
           continue;
         }
 
+        if (IsOSMetadata(leafName) || IsDotFile(leafName)) {
+          continue;
+        }
+
         UNKNOWN_FILE_WARNING(leafName);
         if (!initialized) {
           return NS_ERROR_UNEXPECTED;
@@ -6743,6 +6769,8 @@ nsresult GetUsageOp::TraverseRepository(QuotaManager* aQuotaManager,
         return rv;
       }
 
+      // Unknown files during getting usages are allowed. Just warn if we find
+      // them.
       if (!IsOSMetadata(leafName)) {
         UNKNOWN_FILE_WARNING(leafName);
       }
diff --git a/dom/quota/QuotaCommon.h b/dom/quota/QuotaCommon.h
index a2180f46d1aa..ca46df4e808b 100644
--- a/dom/quota/QuotaCommon.h
+++ b/dom/quota/QuotaCommon.h
@@ -24,6 +24,9 @@
 #define USING_QUOTA_NAMESPACE using namespace mozilla::dom::quota;
 
 #define DSSTORE_FILE_NAME ".DS_Store"
+#define DESKTOP_FILE_NAME ".desktop"
+#define DESKTOP_INI_FILE_NAME "desktop.ini"
+#define THUMBS_DB_FILE_NAME "Thumbs.db"
 
 #define QM_WARNING(...)                                                      \
   do {                                                                       \
diff --git a/dom/quota/QuotaManager.h b/dom/quota/QuotaManager.h
index c760920d6c04..8ffd30d69717 100644
--- a/dom/quota/QuotaManager.h
+++ b/dom/quota/QuotaManager.h
@@ -115,6 +115,10 @@ class QuotaManager final : public BackgroundThreadObject {
   // Returns true if we've begun the shutdown process.
   static bool IsShuttingDown();
 
+  static bool IsOSMetadata(const nsAString& aFileName);
+
+  static bool IsDotFile(const nsAString& aFileName);
+
   bool IsOriginInitialized(const nsACString& aOrigin) const {
     AssertIsOnIOThread();
 
diff --git a/dom/quota/test/unit/test_whiteListFiles.js b/dom/quota/test/unit/test_whiteListFiles.js
new file mode 100644
index 000000000000..05a2efb2c29f
--- /dev/null
+++ b/dom/quota/test/unit/test_whiteListFiles.js
@@ -0,0 +1,55 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * This test is mainly to verify thoes unexpected files are in the white list of
+ * QuotaManager. They aren't expected in the repository but if there are,
+ * QuotaManager shouldn't fail to initialize an origin and getting usage, though
+ * those files aren't managed by QuotaManager.
+ */
+
+async function testSteps()
+{
+  const whiteListFiles = [
+    ".dot-file",
+    "desktop.ini",
+    "Desktop.ini",
+    "Thumbs.db"
+  ];
+
+  for (let whiteListFile of whiteListFiles) {
+    info("Testing " + whiteListFile + " in the repository");
+
+    info("Creating unknown file");
+
+    for (let dir of ["persistenceType dir", "origin dir"]) {
+      let dirPath =
+        dir == "persistenceType dir" ? "storage/default/"
+                                     : "storage/default/http+++example.com/";
+        let file = getRelativeFile(dirPath + whiteListFile);
+        file.create(Ci.nsIFile.NORMAL_FILE_TYPE, parseInt("0644", 8));
+    }
+
+    info("Initializing an origin");
+
+    let request = initOrigin(getPrincipal("http://example.com"), "default");
+    await requestFinished(request);
+
+    info("Resetting");
+
+    request = reset();
+    await requestFinished(request);
+
+    info("Getting usage");
+
+    request = getCurrentUsage(continueToNextStepSync);
+    await requestFinished(request);
+
+    info("Clearing");
+
+    request = clear();
+    await requestFinished(request);
+  }
+}
diff --git a/dom/quota/test/unit/xpcshell.ini b/dom/quota/test/unit/xpcshell.ini
index 6499a01a3428..4b8b95850cc8 100644
--- a/dom/quota/test/unit/xpcshell.ini
+++ b/dom/quota/test/unit/xpcshell.ini
@@ -44,3 +44,4 @@ support-files =
 [test_tempMetadataCleanup.js]
 [test_unknownFiles.js]
 [test_version2_1upgrade.js]
+[test_whiteListFiles.js]
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index b479850b43c6..02048c8e9e1e 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -109,7 +109,6 @@ BytecodeEmitter::BytecodeEmitter(BytecodeEmitter* parent, SharedContext* sc,
       maxFixedSlots(0),
       maxStackDepth(0),
       stackDepth(0),
-      emitLevel(0),
       bodyScopeIndex(UINT32_MAX),
       varEmitterScope(nullptr),
       innermostNestableControl(nullptr),
@@ -2363,7 +2362,12 @@ bool BytecodeEmitter::emitScript(ParseNode* body) {
 
     switchToMain();
 
-    if (!emitLexicalScopeBody(scope->scopeBody())) {
+    ParseNode* scopeBody = scope->scopeBody();
+    if (!emitLexicalScopeBody(scopeBody, EMIT_LINENOTE)) {
+      return false;
+    }
+
+    if (!updateSourceCoordNotes(scopeBody->pn_pos.end)) {
       return false;
     }
 
@@ -2382,10 +2386,10 @@ bool BytecodeEmitter::emitScript(ParseNode* body) {
     if (!emitTree(body)) {
       return false;
     }
-  }
 
-  if (!updateSourceCoordNotes(body->pn_pos.end)) {
-    return false;
+    if (!updateSourceCoordNotes(body->pn_pos.end)) {
+      return false;
+    }
   }
 
   if (!emit1(JSOP_RETRVAL)) {
@@ -4485,20 +4489,6 @@ bool BytecodeEmitter::emitCallSiteObject(CallSiteNode* callSiteObj) {
   return emitObjectPairOp(objbox1, objbox2, JSOP_CALLSITEOBJ);
 }
 
-namespace {
-
-class EmitLevelManager {
-  BytecodeEmitter* bce;
-
- public:
-  explicit EmitLevelManager(BytecodeEmitter* bce) : bce(bce) {
-    bce->emitLevel++;
-  }
-  ~EmitLevelManager() { bce->emitLevel--; }
-};
-
-} /* anonymous namespace */
-
 bool BytecodeEmitter::emitCatch(BinaryNode* catchClause) {
   // We must be nested under a try-finally statement.
   MOZ_ASSERT(innermostNestableControl->is<TryFinallyControl>());
@@ -4723,8 +4713,8 @@ bool BytecodeEmitter::emitHoistedFunctionsInList(ListNode* stmtList) {
   return true;
 }
 
-bool BytecodeEmitter::emitLexicalScopeBody(ParseNode* body,
-                                           EmitLineNumberNote emitLineNote) {
+bool BytecodeEmitter::emitLexicalScopeBody(
+    ParseNode* body, EmitLineNumberNote emitLineNote /* = EMIT_LINENOTE */) {
   if (body->isKind(ParseNodeKind::StatementList) &&
       body->as<ListNode>().hasTopLevelFunctionDeclarations()) {
     // This block contains function statements whose definitions are
@@ -4735,7 +4725,7 @@ bool BytecodeEmitter::emitLexicalScopeBody(ParseNode* body,
     }
   }
 
-  // Line notes were updated by emitLexicalScope.
+  // Line notes were updated by emitLexicalScope or emitScript.
   return emitTree(body, ValueUsage::WantValue, emitLineNote);
 }
 
@@ -8616,8 +8606,6 @@ bool BytecodeEmitter::emitTree(
     return false;
   }
 
-  EmitLevelManager elm(this);
-
   /* Emit notes to tell the current bytecode's source line number.
      However, a couple trees require special treatment; see the
      relevant emitter functions for details. */
@@ -9131,12 +9119,6 @@ bool BytecodeEmitter::emitTree(
       MOZ_ASSERT(0);
   }
 
-  /* bce->emitLevel == 1 means we're last on the stack, so finish up. */
-  if (emitLevel == 1) {
-    if (!updateSourceCoordNotes(pn->pn_pos.end)) {
-      return false;
-    }
-  }
   return true;
 }
 
diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h
index eaf01991059b..0f91c7ce3cd5 100644
--- a/js/src/frontend/BytecodeEmitter.h
+++ b/js/src/frontend/BytecodeEmitter.h
@@ -156,8 +156,6 @@ struct MOZ_STACK_CLASS BytecodeEmitter {
 
   int32_t stackDepth; /* current stack depth in script frame */
 
-  unsigned emitLevel; /* emitTree recursion level */
-
   uint32_t bodyScopeIndex; /* index into scopeList of the body scope */
 
   EmitterScope* varEmitterScope;
diff --git a/python/mozbuild/mozbuild/test/configure/test_toolchain_configure.py b/python/mozbuild/mozbuild/test/configure/test_toolchain_configure.py
index 6d9967ee088a..4543744aea67 100755
--- a/python/mozbuild/mozbuild/test/configure/test_toolchain_configure.py
+++ b/python/mozbuild/mozbuild/test/configure/test_toolchain_configure.py
@@ -263,7 +263,6 @@ CLANG_CL_3_9 = (CLANG_BASE('3.9.0') + VS('18.00.00000') + DEFAULT_C11 +
         '__STDC_VERSION__': False,
         '__cplusplus': '201103L',
     },
-    '-fms-compatibility-version=19.15.26726': VS('19.15.26726')[None],
 }
 
 CLANG_CL_PLATFORM_X86 = FakeCompiler(VS_PLATFORM_X86, GCC_PLATFORM_X86[None])
@@ -928,17 +927,15 @@ class WindowsToolchainTest(BaseToolchainTest):
         language='C++',
     )
     CLANG_CL_3_9_RESULT = CompilerResult(
-        flags=['-Xclang', '-std=gnu99',
-               '-fms-compatibility-version=19.15.26726'],
-        version='19.15.26726',
+        version='18.00.00000',
+        flags=['-Xclang', '-std=gnu99'],
         type='clang-cl',
         compiler='/usr/bin/clang-cl',
         language='C',
     )
     CLANGXX_CL_3_9_RESULT = CompilerResult(
-        flags=['-Xclang', '-std=c++14',
-               '-fms-compatibility-version=19.15.26726'],
-        version='19.15.26726',
+        version='18.00.00000',
+        flags=['-Xclang', '-std=c++14'],
         type='clang-cl',
         compiler='/usr/bin/clang-cl',
         language='C++',