[glib: 1/2] goption: Treat an empty option context parameter string as NULL

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 40a64131d1dfec01ad9adb59eb22d86641bbd027
Author: Philip Withnall <withnall endlessm com>
Date:   Fri May 1 14:37:30 2020 +0100

    goption: Treat an empty option context parameter string as NULL
    
    Otherwise the code ends up calling `gettext ("")`, which returns the
    current translation’s header. The caller should really have provided a
    NULL, parameter string, but the empty string is clear enough.
    
    See
    https://gitlab.freedesktop.org/accountsservice/accountsservice/-/merge_requests/56.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>

 glib/goption.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/glib/goption.c b/glib/goption.c
index b0fb80c94..9f5b977c4 100644
--- a/glib/goption.c
+++ b/glib/goption.c
@@ -241,7 +241,7 @@ struct _GOptionContext
 {
   GList           *groups;
 
-  gchar           *parameter_string;
+  gchar           *parameter_string;  /* (nullable) */
   gchar           *summary;
   gchar           *description;
 
@@ -364,6 +364,11 @@ g_option_context_new (const gchar *parameter_string)
 
   context = g_new0 (GOptionContext, 1);
 
+  /* Clear the empty string to NULL, otherwise we end up calling gettext(""),
+   * which returns the translation header. */
+  if (parameter_string != NULL && *parameter_string == '\0')
+    parameter_string = NULL;
+
   context->parameter_string = g_strdup (parameter_string);
   context->strict_posix = FALSE;
   context->help_enabled = TRUE;