From fca12125306f3fb4e6197a63ff7fb9155eb9a8eb Mon Sep 17 00:00:00 2001
From: Josh Hadley <johadley@adobe.com>
Date: Fri, 29 Sep 2023 14:50:45 -0700
Subject: [PATCH] add guards for h->otl == NULL before calling otlSubtableAdd

Testing in macOS 13.x revealed that there was no check for h->otl == NULL before calling otlSubtableAdd, which accesses h->otl in GPOSFill and GSUBFill routines. Without this check, otlSubtableAdd would fail with a segfault when h->otl was passed in NULL.
---
 c/makeotf/lib/hotconv/GPOS.c | 4 ++++
 c/makeotf/lib/hotconv/GSUB.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/c/makeotf/lib/hotconv/GPOS.c b/c/makeotf/lib/hotconv/GPOS.c
index 63cb918c5..f1ee06201 100644
--- a/c/makeotf/lib/hotconv/GPOS.c
+++ b/c/makeotf/lib/hotconv/GPOS.c
@@ -379,6 +379,10 @@ int GPOSFill(hotCtx g) {
 
     createAnonLookups(g, h);
 
+    if (h->otl == NULL) {
+        return 0;
+    }
+    
     /* Add OTL features */
     /* See GSUB.c::GSUBFill() for an explanation of the subtable order */
 
diff --git a/c/makeotf/lib/hotconv/GSUB.c b/c/makeotf/lib/hotconv/GSUB.c
index 0ee266653..dcc092ce6 100644
--- a/c/makeotf/lib/hotconv/GSUB.c
+++ b/c/makeotf/lib/hotconv/GSUB.c
@@ -217,6 +217,10 @@ int GSUBFill(hotCtx g) {
 
     createAnonLookups(g, h);
 
+    if (h->otl == NULL) {
+        return 0;
+    }
+    
     /* Add OTL features */
 
     /* The font tables are in the order: