Index: glib/gmarkup.c
===================================================================
--- glib/gmarkup.c	(revision 6678)
+++ glib/gmarkup.c	(working copy)
@@ -215,14 +215,20 @@
 {
   GError *tmp_error;
   gchar *s;
+  gchar *s_valid;
   va_list args;
 
   va_start (args, format);
   s = g_strdup_vprintf (format, args);
   va_end (args);
 
-  tmp_error = g_error_new_literal (G_MARKUP_ERROR, code, s);
+  /* Make sure that the GError message is valid UTF-8 even if it is 
+   * complaining about invalid UTF-8 in the markup: */
+  s_valid = _g_utf8_make_valid(s);
+  tmp_error = g_error_new_literal (G_MARKUP_ERROR, code, s_valid);
+
   g_free (s);
+  g_free (s_valid);
 
   g_prefix_error (&tmp_error,
                   _("Error on line %d char %d: "),
Index: ChangeLog
===================================================================
--- ChangeLog	(revision 6678)
+++ ChangeLog	(working copy)
@@ -1,3 +1,12 @@
+2008-03-11  Murray Cumming  <murrayc@murrayc.com>
+
+	Bug 521591 – g_markup_parse_context_parse() creates GError message that 
+	is invalid UTF8.
+
+	* glib/gmarkup.c (set_error): Make sure that the GError::message is 
+	valid UTF-8 even if it is complaining about invalid UTF-8 in the 
+	markup text, using _g_utf8_make_valid().
+
 2008-03-10  Matthias Clasen  <mclasen@redhat.com>
 	
 	* === Released 2.16.1 ===
