diff -ur Thunar-0.8.0_original/plugins/thunar-uca/thunar-uca-editor.c Thunar-0.8.0/plugins/thunar-uca/thunar-uca-editor.c
--- Thunar-0.8.0_original/plugins/thunar-uca/thunar-uca-editor.c	2007-01-20 21:39:07.000000000 +0100
+++ Thunar-0.8.0/plugins/thunar-uca/thunar-uca-editor.c	2007-04-08 21:49:52.071721738 +0200
@@ -484,6 +484,7 @@
   GtkWidget     *chooser;
   gchar         *filename;
   gchar         *s;
+  gchar		*safe_filename;
 
   g_return_if_fail (THUNAR_UCA_IS_EDITOR (uca_editor));
 
@@ -582,9 +583,18 @@
   if (gtk_dialog_run (GTK_DIALOG (chooser)) == GTK_RESPONSE_ACCEPT)
     {
       filename = gtk_file_chooser_get_filename (GTK_FILE_CHOOSER (chooser));
-      s = g_strconcat (filename, " %f", NULL);
+      /* Bug 3105: Add quotes, if the path to filename contains spaces */
+      if (strstr (filename, " ") == NULL)
+        /* No spaces in filename, it's safe to use the filename as it is */
+        safe_filename = g_strdup(filename);
+      else
+        /* filename contains spaces, add quotes */
+        safe_filename = g_strdup_printf ("\"%s\"", filename);
+      
+      s = g_strconcat (safe_filename, " %f", NULL);
       gtk_entry_set_text (GTK_ENTRY (uca_editor->command_entry), s);
       g_free (filename);
+      g_free (safe_filename);
       g_free (s);
     }