Ensure that the widget is fully onscreen before taking a screenshot.

Otherwise X emits a BadMatch and gtk kills the process (!).
Fix #8220

1 files changed, 23 insertions, 1 deletions

diff --git a/src/sugar/sugar-preview.c b/src/sugar/sugar-preview.c
index 42fb9d3..44b83e4 100644
--- a/src/sugar/sugar-preview.c
+++ b/src/sugar/sugar-preview.c
@@ -69,16 +69,38 @@ sugar_preview_clear(SugarPreview *preview)
     }
 }
 
+static gboolean
+widget_is_off_screen(GtkWidget *widget)
+{
+    GdkScreen *screen;
+    gint x, y, width, height;
+
+    screen = gtk_widget_get_screen(widget);
+
+    gdk_window_get_geometry(widget->window, &x, &y, &width, &height, NULL);
+
+    return (x < 0 || y < 0 ||
+            x + width > gdk_screen_get_width(screen) ||
+            y + height > gdk_screen_get_height(screen));
+}
+
 void
-sugar_preview_take_screenshot(SugarPreview *preview, GdkDrawable *drawable)
+sugar_preview_take_screenshot(SugarPreview *preview, GtkWidget *widget)
 {
+    GdkDrawable *drawable;
     GdkScreen *screen;
     GdkVisual *visual;
     GdkColormap *colormap;
     gint width, height;
 
+    if (widget->window == NULL || widget_is_off_screen(widget)) {
+        return;
+    }
+    
     sugar_preview_clear(preview);
 
+    drawable = GDK_DRAWABLE(widget->window);
+
     gdk_drawable_get_size(drawable, &width, &height);
 
     screen = gdk_drawable_get_screen(drawable);