Restore Explorer shell if setup leaves it stopped (#2552)

Restore Explorer shell after successful setup

Src/Setup/Setup.cpp

@@ -47,6 +47,69 @@ struct Chunk
 	int start1, start2, len;
 };
 
+static bool IsExplorerShellRunning( void )
+{
+	HWND shellWindow=GetShellWindow();
+	if (!shellWindow)
+		return false;
+
+	DWORD shellProcessId=0;
+	GetWindowThreadProcessId(shellWindow,&shellProcessId);
+	if (!shellProcessId)
+		return false;
+
+	DWORD currentSession=0;
+	DWORD shellSession=0;
+	if (!ProcessIdToSessionId(GetCurrentProcessId(),&currentSession) ||
+		!ProcessIdToSessionId(shellProcessId,&shellSession) ||
+		currentSession!=shellSession)
+	{
+		return false;
+	}
+
+	HANDLE process=OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION,FALSE,shellProcessId);
+	if (!process)
+		return false;
+
+	wchar_t path[_MAX_PATH];
+	DWORD pathSize=_countof(path);
+	bool isExplorer=false;
+	if (QueryFullProcessImageName(process,0,path,&pathSize))
+		isExplorer=_wcsicmp(PathFindFileName(path),L"explorer.exe")==0;
+
+	CloseHandle(process);
+	return isExplorer;
+}
+
+static void RestoreExplorerShellIfNeeded( bool wasRunning )
+{
+	if (!wasRunning)
+		return;
+
+	// Restart Manager normally brings Explorer back before msiexec exits.
+	// Give it a short grace period before applying our fallback so we don't
+	// race a normal restart or create an extra Explorer process.
+	for (int i=0;i<50;i++)
+	{
+		if (IsExplorerShellRunning())
+			return;
+		Sleep(100);
+	}
+
+	wchar_t explorerPath[_MAX_PATH];
+	UINT len=GetWindowsDirectory(explorerPath,_countof(explorerPath));
+	if (!len || len>=_countof(explorerPath) || !PathAppend(explorerPath,L"explorer.exe"))
+		return;
+
+	STARTUPINFO startupInfo={sizeof(startupInfo)};
+	PROCESS_INFORMATION processInfo={};
+	if (CreateProcess(explorerPath,NULL,NULL,NULL,FALSE,0,NULL,NULL,&startupInfo,&processInfo))
+	{
+		CloseHandle(processInfo.hThread);
+		CloseHandle(processInfo.hProcess);
+	}
+}
+
 static void WriteFileXOR( HANDLE hFile, const unsigned char *buf, int size )
 {
 	if (size>0)
@@ -409,6 +472,11 @@ int APIENTRY wWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCm
 	if (extractType == ARM64)
 		Wow64DisableWow64FsRedirection(&wow64FsRedirVal);
 
+	// Remember whether this interactive session had the Explorer desktop shell.
+	// If Restart Manager closes it during MSI processing but fails to bring it
+	// back, restore only the shell that was present before setup started.
+	const bool explorerWasRunning=IsExplorerShellRunning();
+
 	// start the installer
 	STARTUPINFO startupInfo={sizeof(startupInfo)};
 	PROCESS_INFORMATION processInfo;
@@ -438,6 +506,12 @@ int APIENTRY wWinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCm
 		GetExitCodeProcess(processInfo.hProcess,&code);
 		CloseHandle(processInfo.hProcess);
 		DeleteFile(msiName);
+
+		// Only repair the shell after a successful transaction. Reboot-required
+		// outcomes deliberately keep Windows Installer in control of recovery.
+		if (code==ERROR_SUCCESS)
+			RestoreExplorerShellIfNeeded(explorerWasRunning);
+
 		return code;
 	}
 }

Src/StartMenu/StartMenuDLL/ItemManager.cpp

@@ -3337,19 +3337,19 @@ void CItemManager::LoadCacheFile( void )
 				info.iconColor=data.iconColor;
 				info.iconIndex=data.iconIndex;
 
-				info.smallIcon=data.smallIcon<(int)remapIcons.size()?remapIcons[data.smallIcon]:NULL;
+				info.smallIcon=data.smallIcon>=0 && (size_t)data.smallIcon<remapIcons.size()?remapIcons[data.smallIcon]:NULL;
 				if (!info.smallIcon)
 				{
 					info.validFlags&=~INFO_SMALL_ICON;
 					info.smallIcon=m_DefaultSmallIcon;
 				}
-				info.largeIcon=data.largeIcon<(int)remapIcons.size()?remapIcons[data.largeIcon]:NULL;
+				info.largeIcon=data.largeIcon>=0 && (size_t)data.largeIcon<remapIcons.size()?remapIcons[data.largeIcon]:NULL;
 				if (!info.largeIcon)
 				{
 					info.validFlags&=~INFO_LARGE_ICON;
 					info.largeIcon=m_DefaultLargeIcon;
 				}
-				info.extraLargeIcon=data.extraLargeIcon<(int)remapIcons.size()?remapIcons[data.extraLargeIcon]:NULL;
+				info.extraLargeIcon=data.extraLargeIcon>=0 && (size_t)data.extraLargeIcon<remapIcons.size()?remapIcons[data.extraLargeIcon]:NULL;
 				if (!info.extraLargeIcon)
 				{
 					info.validFlags&=~INFO_EXTRA_LARGE_ICON;
@@ -3422,7 +3422,7 @@ DWORD CALLBACK CItemManager::SaveCacheFileThread( void *param )
 		RWLock lock(pThis,false,RWLOCK_ICONS);
 		for (std::multimap<unsigned int,IconInfo>::const_iterator it=pThis->m_IconInfos.begin();it!=pThis->m_IconInfos.end();++it)
 		{
-			if (!it->second.PATH.IsEmpty() && it->second.PATH[1]!='#' && it->first!=0)
+			if (!it->second.bTemp && !it->second.bMetro && !it->second.PATH.IsEmpty() && it->second.PATH[1]!='#' && it->first!=0)
 				iconInfos.push_back(&*it);
 		}
 	}
@@ -3433,7 +3433,7 @@ DWORD CALLBACK CItemManager::SaveCacheFileThread( void *param )
 		RWLock lock(pThis,false,RWLOCK_ITEMS);
 		for (std::multimap<unsigned int,ItemInfo>::const_iterator it=pThis->m_ItemInfos.begin();it!=pThis->m_ItemInfos.end();++it)
 		{
-			if (it->first!=0)
+			if (!it->second.bTemp && it->first!=0)
 				itemInfos.push_back(&*it);
 		}
 		for (std::set<unsigned int>::const_iterator it=pThis->m_BlackListInfos10.begin();it!=pThis->m_BlackListInfos10.end();++it)
@@ -3566,6 +3566,15 @@ void CItemManager::SaveCacheFile( void )
 
 void CItemManager::ClearCache( void )
 {
+	// The save thread keeps pointers to persistent cache entries while serializing them.
+	// Let it finish before clearing the containers those pointers refer to.
+	if (m_SaveCacheThread)
+	{
+		WaitForSingleObject(m_SaveCacheThread,INFINITE);
+		CloseHandle(m_SaveCacheThread);
+		m_SaveCacheThread=NULL;
+	}
+
 	Lock cleanupLock(this,LOCK_CLEANUP);
 	RWLock itemLock(this,true,RWLOCK_ITEMS);
 	RWLock iconLock(this,true,RWLOCK_ICONS);

Src/StartMenu/StartMenuDLL/MenuCommands.cpp

@@ -63,14 +63,6 @@ static auto ExecuteOnSTAThread(TFunc&& func) -> decltype(func())
 	return result;
 }
 
-// Wrapper for IContextMenu::InvokeCommand that runs on separate STA thread and pumps messages
-static HRESULT InvokeCommandSafe(IContextMenu* pMenu, LPCMINVOKECOMMANDINFO pInfo)
-{
-	return ExecuteOnSTAThread([&]() {
-		return pMenu->InvokeCommand(pInfo);
-	});
-}
-
 // Wrapper for SHOpenFolderAndSelectItems that runs on separate STA thread and pumps messages
 static HRESULT SHOpenFolderAndSelectItemsSafe(PCIDLIST_ABSOLUTE pidlFolder, UINT cidl, PCUITEMID_CHILD_ARRAY apidl, DWORD dwFlags)
 {
@@ -3182,12 +3174,13 @@ void CMenuContainer::ActivateItem( int index, TActivateType type, const POINT *p
 			{
 				HRESULT hr{};
 				auto verb = GetContextMenuItemVerb(pInvokeMenu, (UINT_PTR)info.lpVerbW);
-				// if the verb is "properties", we need to invoke it directly in this UI thread (as it needs to be called on thread that crated context menu object),
-				// otherwise we will invoke the command on separate STA thread to make sure it won't block UI thread
-				if (verb.CompareNoCase(L"properties") == 0)
-					hr = pInvokeMenu->InvokeCommand((LPCMINVOKECOMMANDINFO)&info);
+				// "opencontaining" may block the UI thread on recent Windows 11 versions.
+				// Use the shell API on a worker STA for that operation, without passing
+				// the apartment-bound IContextMenu interface to another thread.
+				if (verb.CompareNoCase(L"opencontaining") == 0)
+					hr = SHOpenFolderAndSelectItemsSafe(pItemPidl1, 0, NULL, 0);
 				else
-					hr = InvokeCommandSafe(pInvokeMenu, (LPCMINVOKECOMMANDINFO)&info);
+					hr = pInvokeMenu->InvokeCommand((LPCMINVOKECOMMANDINFO)&info);
 				LOG_MENU(LOG_EXECUTE,L"Invoke command, ptr=%p, res=%d",this,hr);
 				executeSuccess=SUCCEEDED(hr);
 			}

Src/StartMenu/StartMenuDLL/MenuContainer.cpp

@@ -2537,10 +2537,11 @@ void CMenuContainer::InitItems( void )
 			}
 	}
 
-	if (m_Items.empty() && m_Path1[0] && m_pDropFolder[0])
+	if (!m_bSubMenu && m_Items.empty() && m_Path1[0] && m_pDropFolder[0])
 	{
-		// add (Empty) item to the empty submenus
-		MenuItem item(m_bSubMenu?MENU_EMPTY:MENU_EMPTY_TOP);
+		// Keep the top-level drop target placeholder. Submenus defer their
+		// empty-state decision until after custom/standard items are appended.
+		MenuItem item(MENU_EMPTY_TOP);
 		item.name=FindTranslation(L"Menu.Empty",L"(Empty)");
 		m_Items.push_back(item);
 	}