Fix FS#10841. Thanks to Thomas Martitz for spotting what was wrong.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23914 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 10 insertions, 3 deletions

diff --git a/apps/gui/usb_screen.c b/apps/gui/usb_screen.c
index 29d88da..d3baa5b 100644
--- a/apps/gui/usb_screen.c
+++ b/apps/gui/usb_screen.c
@@ -128,9 +128,10 @@ struct usb_screen_vps_t
 };
 
 #ifdef HAVE_LCD_BITMAP
-static void usb_screen_fix_viewports(struct screen *screen,
+static bool usb_screen_fix_viewports(struct screen *screen,
         struct usb_screen_vps_t *usb_screen_vps)
 {
+    bool theme_needs_undo = false;
     int logo_width, logo_height;
     struct viewport *parent = &usb_screen_vps->parent;
     struct viewport *logo = &usb_screen_vps->logo;
@@ -150,7 +151,10 @@ static void usb_screen_fix_viewports(struct screen *screen,
 
     viewport_set_defaults(parent, screen->screen_type);
     if (parent->width < logo_width || parent->height < logo_height)
+    {
+        theme_needs_undo = true;
         viewportmanager_theme_enable(screen->screen_type, false, parent);
+    }
 
     *logo = *parent;
     logo->x = parent->x + parent->width - logo_width;
@@ -174,6 +178,7 @@ static void usb_screen_fix_viewports(struct screen *screen,
         }
     }
 #endif
+    return theme_needs_undo;
 }
 #endif
 
@@ -240,6 +245,7 @@ static void usb_screens_draw(struct usb_screen_vps_t *usb_screen_vps_ar)
 void gui_usb_screen_run(void)
 {
     int i;
+    bool screen_theme_needs_undo[NB_SCREENS];
     struct usb_screen_vps_t usb_screen_vps_ar[NB_SCREENS];
 #if defined HAVE_TOUCHSCREEN
     enum touchscreen_mode old_mode = touchscreen_get_mode();
@@ -264,7 +270,7 @@ void gui_usb_screen_run(void)
 
         screen->set_viewport(NULL);
 #ifdef HAVE_LCD_BITMAP
-        usb_screen_fix_viewports(screen, &usb_screen_vps_ar[i]);
+        screen_theme_needs_undo[i] = usb_screen_fix_viewports(screen, &usb_screen_vps_ar[i]);
 #endif
     }
 
@@ -311,7 +317,8 @@ void gui_usb_screen_run(void)
     FOR_NB_SCREENS(i)
     {
         screens[i].backlight_on();
-        viewportmanager_theme_undo(i);
+        if(screen_theme_needs_undo[i])
+            viewportmanager_theme_undo(i);
     }
 
 }