diff -r 9fb13a5dde3b -r 783eff3047bc test/harness/testcase.c
--- a/test/harness/testcase.c	Mon Sep 23 21:18:27 2013 +0100
+++ b/test/harness/testcase.c	Sat Oct 05 21:37:31 2013 +0100
@@ -527,6 +527,31 @@
 }
 
 /*
+ * Run a testcase, returning FALSE on error.
+ * Bookloupe's output or a suitable error message will be shown.
+ */
+gboolean testcase_show_output(Testcase *testcase)
+{
+    gboolean r;
+    gchar *output;
+    GError *error=NULL;
+    r=testcase_create_input_files(testcase,&error);
+    if (r)
+    {
+	r&=testcase_spawn_bookloupe(testcase,&output,&error);
+	r&=testcase_remove_input_files(testcase,&error);
+    }
+    if (r)
+	g_print("%s",output);
+    else
+    {
+	g_print("%s\n",error->message);
+	g_error_free(error);
+    }
+    return r;
+}
+
+/*
  * Free a testcase warning.
  */
 void testcase_warning_free(TestcaseWarning *warning)