--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/OT/Layout/GSUB/GSUB.hh	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,61 @@
+#ifndef OT_LAYOUT_GSUB_GSUB_HH
+#define OT_LAYOUT_GSUB_GSUB_HH
+
+#include "../../../hb-ot-layout-gsubgpos.hh"
+#include "Common.hh"
+#include "SubstLookup.hh"
+
+namespace OT {
+
+using Layout::GSUB_impl::SubstLookup;
+
+namespace Layout {
+
+/*
+ * GSUB -- Glyph Substitution
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/gsub
+ */
+
+struct GSUB : GSUBGPOS
+{
+  using Lookup = SubstLookup;
+
+  static constexpr hb_tag_t tableTag = HB_OT_TAG_GSUB;
+
+  const SubstLookup& get_lookup (unsigned int i) const
+  { return static_cast<const SubstLookup &> (GSUBGPOS::get_lookup (i)); }
+
+  bool subset (hb_subset_context_t *c) const
+  {
+    hb_subset_layout_context_t l (c, tableTag);
+    return GSUBGPOS::subset<SubstLookup> (&l);
+  }
+
+  bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (GSUBGPOS::sanitize<SubstLookup> (c));
+  }
+
+  HB_INTERNAL bool is_blocklisted (hb_blob_t *blob,
+                                   hb_face_t *face) const;
+
+  void closure_lookups (hb_face_t      *face,
+                        const hb_set_t *glyphs,
+                        hb_set_t       *lookup_indexes /* IN/OUT */) const
+  { GSUBGPOS::closure_lookups<SubstLookup> (face, glyphs, lookup_indexes); }
+
+  typedef GSUBGPOS::accelerator_t<GSUB> accelerator_t;
+};
+
+
+}
+
+struct GSUB_accelerator_t : Layout::GSUB::accelerator_t {
+  GSUB_accelerator_t (hb_face_t *face) : Layout::GSUB::accelerator_t (face) {}
+};
+
+
+}
+
+#endif  /* OT_LAYOUT_GSUB_GSUB_HH */