Windows: when /silent specified in command line, avoid performing any WIN32 UI calls. This fixes issue of current application losing focus when VeraCrypt is run with /quit /silent (cf https://github.com/veracrypt/VeraCrypt/issues/274)

src/Common/Dlgcode.c

@@ -1790,13 +1790,13 @@ static int g_waitCursorCounter = 0;
 void
 WaitCursor ()
 {
-	static HCURSOR hcWait;
+	static HCURSOR hcWait = NULL;
 	if (hcWait == NULL)
 		hcWait = LoadCursor (NULL, IDC_WAIT);
 
 	if ((g_waitCursorCounter == 0) || (hCursor != hcWait))
 	{
-		SetCursor (hcWait);
+		if (!Silent) SetCursor (hcWait);
 		hCursor = hcWait;
 	}
 	g_waitCursorCounter++;
@@ -1805,14 +1805,14 @@ WaitCursor ()
 void
 NormalCursor ()
 {
-	static HCURSOR hcArrow;
+	static HCURSOR hcArrow = NULL;
 	if (hcArrow == NULL)
 		hcArrow = LoadCursor (NULL, IDC_ARROW);
 	if (g_waitCursorCounter > 0)
 		g_waitCursorCounter--;
 	if (g_waitCursorCounter == 0)
 	{
-		SetCursor (hcArrow);
+		if (!Silent) SetCursor (hcArrow);
 		hCursor = NULL;
 	}
 }
@@ -1820,12 +1820,12 @@ NormalCursor ()
 void
 ArrowWaitCursor ()
 {
-	static HCURSOR hcArrowWait;
+	static HCURSOR hcArrowWait = NULL;
 	if (hcArrowWait == NULL)
 		hcArrowWait = LoadCursor (NULL, IDC_APPSTARTING);
 	if ((g_waitCursorCounter == 0) || (hCursor != hcArrowWait))
 	{
-		SetCursor (hcArrowWait);
+		if (!Silent) SetCursor (hcArrowWait);
 		hCursor = hcArrowWait;
 	}
 	g_waitCursorCounter++;
@@ -1833,7 +1833,7 @@ ArrowWaitCursor ()
 
 void HandCursor ()
 {
-	static HCURSOR hcHand;
+	static HCURSOR hcHand = NULL;
 	if (hcHand == NULL)
 		hcHand = LoadCursor (NULL, IDC_HAND);
 	SetCursor (hcHand);

src/Mount/Mount.c

@@ -378,6 +378,10 @@ static void localcleanup (void)
 }
 
 void RefreshMainDlg (HWND hwndDlg)
+{
+	if (Silent)
+		LoadDriveLetters (hwndDlg, NULL, 0);
+	else
 	{
 		int drive = (wchar_t) (HIWORD (GetSelectedLong (GetDlgItem (hwndDlg, IDC_DRIVELIST))));
 
@@ -385,6 +389,7 @@ void RefreshMainDlg (HWND hwndDlg)
 		LoadDriveLetters (hwndDlg, GetDlgItem (hwndDlg, IDC_DRIVELIST), drive);
 		EnableDisableButtons (hwndDlg);
 	}
+}
 
 void EndMainDlg (HWND hwndDlg)
 {
@@ -427,6 +432,8 @@ static void InitMainDialog (HWND hwndDlg)
 	wchar_t *str;
 	int i;
 
+	if (!Silent)
+	{
 		/* Call the common dialog init code */
 		InitDialog (hwndDlg);
 		LocalizeDialog (hwndDlg, NULL);
@@ -484,6 +491,7 @@ static void InitMainDialog (HWND hwndDlg)
 
 		// Disable menu item for changing system header key derivation algorithm until it's implemented
 		EnableMenuItem (GetMenu (hwndDlg), IDM_CHANGE_SYS_HEADER_KEY_DERIV_ALGO, MF_GRAYED);
+	}
 
 	try
 	{
@@ -497,6 +505,10 @@ static void InitMainDialog (HWND hwndDlg)
 	// initialize the list of devices available for mounting as early as possible
 	UpdateMountableHostDeviceList ();
 
+	if (Silent)
+		LoadDriveLetters (hwndDlg, NULL, 0);
+	else
+	{
 		// Resize the logo bitmap if the user has a non-default DPI
 		if (ScreenDPI != USER_DEFAULT_SCREEN_DPI
 			&& hbmLogoBitmapRescaled == NULL)	// If not re-called (e.g. after language pack change)
@@ -523,6 +535,7 @@ static void InitMainDialog (HWND hwndDlg)
 		SendMessage (GetDlgItem (hwndDlg, IDC_NO_HISTORY), BM_SETCHECK, bHistory ? BST_UNCHECKED : BST_CHECKED, 0);
 		EnableDisableButtons (hwndDlg);
 	}
+}
 
 void EnableDisableButtons (HWND hwndDlg)
 {
@@ -1564,7 +1577,7 @@ static void LaunchVolExpander (HWND hwndDlg)
 void LoadDriveLetters (HWND hwndDlg, HWND hTree, int drive)
 {
 	// Remember the top-most visible item
-	int lastTopMostVisibleItem = ListView_GetTopIndex (hTree);
+	int lastTopMostVisibleItem = (!Silent && hTree)? ListView_GetTopIndex (hTree) : 0;
 
 	wchar_t *szDriveLetters[]=
 	{L"A:", L"B:", L"C:", L"D:",
@@ -1618,6 +1631,9 @@ void LoadDriveLetters (HWND hwndDlg, HWND hTree, int drive)
 	if (dwUsedDrives == 0)
 			Warning ("DRIVELETTERS", hwndDlg);
 
+	if (Silent)
+		return;
+
 	if(drive == 0)
 		ListView_DeleteAllItems(hTree);
 
@@ -5182,7 +5198,7 @@ retry:
 			return FALSE;
 		}
 
-		if (interact)
+		if (interact && !Silent)
 			MessageBoxW (hwndDlg, GetString ("UNMOUNT_FAILED"), lpszTitle, MB_ICONERROR);
 	}
 	else
@@ -5485,6 +5501,9 @@ static BOOL MountAllDevices (HWND hwndDlg, BOOL bPasswordPrompt)
 	param.bPasswordPrompt = bPasswordPrompt;
 	param.bRet = FALSE;
 
+	if (Silent)
+		mountAllDevicesThreadProc (&param, hwndDlg);
+	else
 		ShowWaitDialog (hwndDlg, FALSE, mountAllDevicesThreadProc, &param);
 
 	return param.bRet;
@@ -6612,6 +6631,9 @@ BOOL CALLBACK MainDialogProc (HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
 
 			ExtractCommandLine (hwndDlg, (wchar_t *) lParam);
 
+			if (Silent && !Quit)
+				Silent = FALSE;
+
 			try
 			{
 				BootEncObj->SetParentWindow (hwndDlg);
@@ -6824,10 +6846,10 @@ BOOL CALLBACK MainDialogProc (HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
 						if (bExplore)
 							OpenVolumeExplorerWindow (szDriveLetter[0] - L'A');
 
-						RefreshMainDlg(hwndDlg);
 
 						if(!Silent)
 						{
+							RefreshMainDlg(hwndDlg);
 							// Check for problematic file extensions (exe, dll, sys)
 							if (CheckFileExtension (szFileName))
 								Warning ("EXE_FILE_EXTENSION_MOUNT_WARNING", hwndDlg);
@@ -6917,6 +6939,15 @@ BOOL CALLBACK MainDialogProc (HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
 						TaskBarIconRemove (hwndDlg);
 					exit (exitCode);
 				}
+				else
+				{
+					if (Silent)
+					{
+						Silent = FALSE;
+						InitMainDialog (hwndDlg);
+						RefreshMainDlg(hwndDlg);
+					}
+				}
 			}
 
 			// No command line arguments or only /volume => bring active instance
@@ -9531,7 +9562,7 @@ static BOOL MountFavoriteVolumeBase (HWND hwnd, const FavoriteVolume &favorite,
 			else
 				mountOptions.ProtectedHidVolPkcs5Prf = CmdVolumePkcs5;
 			mountOptions.ProtectedHidVolPim = CmdVolumePim;
-			if (DialogBoxParamW (hInst, MAKEINTRESOURCEW (IDD_MOUNT_OPTIONS), hwnd, (DLGPROC) MountOptionsDlgProc, (LPARAM) &mountOptions) == IDCANCEL)
+			if (Silent || (DialogBoxParamW (hInst, MAKEINTRESOURCEW (IDD_MOUNT_OPTIONS), hwnd, (DLGPROC) MountOptionsDlgProc, (LPARAM) &mountOptions) == IDCANCEL))
 			{
 				status = FALSE;
 				goto skipMount;