[pango/add-null-checkds] Add some NULL checks

[Matthias Clasen <matthiasc src gnome org>]

commit 7b3182a3b5427137557d257f7024a5078a096fc3
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun May 9 00:45:31 2021 -0400

    Add some NULL checks
    
    Originally suggested by Philipp Withnall in
    https://bugzilla.gnome.org/show_bug.cgi?id=778655
    
    Fixes: #268

 pango/pangocoretext-fontmap.c | 3 ++-
 pango/pangofc-fontmap.c       | 3 ++-
 pango/pangowin32-fontmap.c    | 3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/pango/pangocoretext-fontmap.c b/pango/pangocoretext-fontmap.c
index 09437b4a..81bf7bf7 100644
--- a/pango/pangocoretext-fontmap.c
+++ b/pango/pangocoretext-fontmap.c
@@ -529,7 +529,8 @@ pango_core_text_face_list_sizes (PangoFontFace  *face,
                                  int            *n_sizes)
 {
   *n_sizes = 0;
-  *sizes = NULL;
+  if (sizes)
+    *sizes = NULL;
 }
 
 G_DEFINE_TYPE (PangoCoreTextFace, pango_core_text_face, PANGO_TYPE_FONT_FACE);
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 7966a8cd..f74b2c15 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -2904,7 +2904,8 @@ pango_fc_face_list_sizes (PangoFontFace  *face,
   FcObjectSet *objectset;
   FcFontSet *fonts;
 
-  *sizes = NULL;
+  if (sizes)
+    *sizes = NULL;
   *n_sizes = 0;
   if (G_UNLIKELY (!fcface->family || !fcface->family->fontmap))
     return;
diff --git a/pango/pangowin32-fontmap.c b/pango/pangowin32-fontmap.c
index e5e81bba..18d4544e 100644
--- a/pango/pangowin32-fontmap.c
+++ b/pango/pangowin32-fontmap.c
@@ -1794,7 +1794,8 @@ pango_win32_face_list_sizes (PangoFontFace  *face,
    * for scalable fonts it's simple, and currently we only have such
    * see : pango_win32_enum_proc(), TRUETYPE_FONTTYPE
    */
-  *sizes = NULL;
+  if (sizes)
+    *sizes = NULL;
   *n_sizes = 0;
 }