[pango/issue-489] Initialise out arguments

[Emmanuele Bassi <ebassi src gnome org>]

commit 8ed55ed79ee1319b846f6d6954906a6ec6e19869
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri Jul 3 11:49:08 2020 +0100

    Initialise out arguments
    
    If we bail out early, we end up with uninitialised data and no way for a
    caller to know that happened.
    
    Fixes: #489

 pango/pangofc-fontmap.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index b2c44300..ec504094 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -2842,6 +2842,12 @@ pango_fc_family_list_faces (PangoFontFamily  *family,
 {
   PangoFcFamily *fcfamily = PANGO_FC_FAMILY (family);
 
+  if (faces)
+    *faces = NULL;
+
+  if (n_faces)
+    *n_faces = 0;
+
   if (G_UNLIKELY (!fcfamily->fontmap))
     return;