1 files changed, 43 insertions, 0 deletions
diff --git a/freetype-2.10.4-avoid-invalid-face-index.patch b/freetype-2.10.4-avoid-invalid-face-index.patch
new file mode 100644
index 0000000..55c09bd
--- /dev/null
+++ b/freetype-2.10.4-avoid-invalid-face-index.patch
@@ -0,0 +1,43 @@
+From 53dfdcd8198d2b3201a23c4bad9190519ba918db Mon Sep 17 00:00:00 2001
+From: Werner Lemberg <wl@gnu.org>
+Date: Thu, 17 Mar 2022 19:24:16 +0100
+Subject: [PATCH] [sfnt] Avoid invalid face index.
+
+Fixes #1138.
+
+* src/sfnt/sfobjs.c (sfnt_init_face), src/sfnt/sfwoff2.c (woff2_open_font):
+Check `face_index` before decrementing.
+---
+ src/sfnt/sfobjs.c  | 2 +-
+ src/sfnt/sfwoff2.c | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/sfnt/sfobjs.c b/src/sfnt/sfobjs.c
+index f9d4d3858..9771c35df 100644
+--- a/src/sfnt/sfobjs.c
++++ b/src/sfnt/sfobjs.c
+@@ -566,7 +566,7 @@
+     face_index = FT_ABS( face_instance_index ) & 0xFFFF;
+ 
+     /* value -(N+1) requests information on index N */
+-    if ( face_instance_index < 0 )
++    if ( face_instance_index < 0 && face_index > 0 )
+       face_index--;
+ 
+     if ( face_index >= face->ttc_header.count )
+diff --git a/src/sfnt/sfwoff2.c b/src/sfnt/sfwoff2.c
+index cb1e0664a..165b875e5 100644
+--- a/src/sfnt/sfwoff2.c
++++ b/src/sfnt/sfwoff2.c
+@@ -2085,7 +2085,7 @@
+     /* Validate requested face index. */
+     *num_faces = woff2.num_fonts;
+     /* value -(N+1) requests information on index N */
+-    if ( *face_instance_index < 0 )
++    if ( *face_instance_index < 0 && face_index > 0 )
+       face_index--;
+ 
+     if ( face_index >= woff2.num_fonts )
+-- 
+2.35.1
+