[gthumb] [adjust_colors] Fixed crash when clicking apply with no changes

[Paolo Bacchilega <paobac src gnome org>]

commit d6a681eefbf3c5a944b0397a79f045d03f04fcc3
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Feb 26 11:59:37 2010 +0100

    [adjust_colors] Fixed crash when clicking apply with no changes
    
    [bug #611156]

 .../file_tools/gth-file-tool-adjust-colors.c       |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)
---
diff --git a/extensions/file_tools/gth-file-tool-adjust-colors.c b/extensions/file_tools/gth-file-tool-adjust-colors.c
index 2eb040f..60f448f 100644
--- a/extensions/file_tools/gth-file-tool-adjust-colors.c
+++ b/extensions/file_tools/gth-file-tool-adjust-colors.c
@@ -208,12 +208,15 @@ static void
 ok_button_clicked_cb (GtkButton               *button,
 		      GthFileToolAdjustColors *self)
 {
-	GtkWidget *window;
-	GtkWidget *viewer_page;
+	if (self->priv->dest_pixbuf != NULL) {
+		GtkWidget *window;
+		GtkWidget *viewer_page;
+
+		window = gth_file_tool_get_window (GTH_FILE_TOOL (self));
+		viewer_page = gth_browser_get_viewer_page (GTH_BROWSER (window));
+		gth_image_viewer_page_set_pixbuf (GTH_IMAGE_VIEWER_PAGE (viewer_page), self->priv->dest_pixbuf, TRUE);
+	}
 
-	window = gth_file_tool_get_window (GTH_FILE_TOOL (self));
-	viewer_page = gth_browser_get_viewer_page (GTH_BROWSER (window));
-	gth_image_viewer_page_set_pixbuf (GTH_IMAGE_VIEWER_PAGE (viewer_page), self->priv->dest_pixbuf, TRUE);
 	gth_file_tool_hide_options (GTH_FILE_TOOL (self));
 }