diff --git a/src/gui.c b/src/gui.c
index 3b0ebac..68c64d2 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -5641,3 +5641,26 @@
     return NUL;
 }
 
+/*
+ * If the "--gui-log-file fname" argument is given write the dialog title and
+ * message to a file and return TRUE.  Otherwise return FALSE.
+ * When there is any problem opening the file or writing to the file this is
+ * ignored, showing the dialog might get the test to get stuck.
+ */
+    int
+gui_dialog_log(char_u *title, char_u *message)
+{
+    char_u  *fname = get_gui_dialog_file();
+    FILE    *fd;
+
+    if (fname == NULL)
+	return FALSE;
+
+    fd = mch_fopen((char *)fname, "a");
+    if (fd != NULL)
+    {
+	fprintf(fd, "%s: %s\n", title, message);
+	fclose(fd);
+    }
+    return TRUE;
+}