--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/harfbuzz/src/OT/Layout/GPOS/PairSet.hh	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,203 @@
+#ifndef OT_LAYOUT_GPOS_PAIRSET_HH
+#define OT_LAYOUT_GPOS_PAIRSET_HH
+
+#include "PairValueRecord.hh"
+
+namespace OT {
+namespace Layout {
+namespace GPOS_impl {
+
+
+template <typename Types>
+struct PairSet
+{
+  template <typename Types2>
+  friend struct PairPosFormat1_3;
+
+  using PairValueRecord = GPOS_impl::PairValueRecord<Types>;
+
+  protected:
+  HBUINT16              len;    /* Number of PairValueRecords */
+  PairValueRecord       firstPairValueRecord;
+                                /* Array of PairValueRecords--ordered
+                                 * by GlyphID of the second glyph */
+  public:
+  DEFINE_SIZE_MIN (2);
+
+  struct sanitize_closure_t
+  {
+    const ValueFormat *valueFormats;
+    unsigned int len1; /* valueFormats[0].get_len() */
+    unsigned int stride; /* 1 + len1 + len2 */
+  };
+
+  bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
+  {
+    TRACE_SANITIZE (this);
+    if (!(c->check_struct (this)
+       && c->check_range (&firstPairValueRecord,
+                          len,
+                          HBUINT16::static_size,
+                          closure->stride))) return_trace (false);
+
+    unsigned int count = len;
+    const PairValueRecord *record = &firstPairValueRecord;
+    return_trace (closure->valueFormats[0].sanitize_values_stride_unsafe (c, this, &record->values[0], count, closure->stride) &&
+                  closure->valueFormats[1].sanitize_values_stride_unsafe (c, this, &record->values[closure->len1], count, closure->stride));
+  }
+
+  bool intersects (const hb_set_t *glyphs,
+                   const ValueFormat *valueFormats) const
+  {
+    unsigned int len1 = valueFormats[0].get_len ();
+    unsigned int len2 = valueFormats[1].get_len ();
+    unsigned int record_size = HBUINT16::static_size * (1 + len1 + len2);
+
+    const PairValueRecord *record = &firstPairValueRecord;
+    unsigned int count = len;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (glyphs->has (record->secondGlyph))
+        return true;
+      record = &StructAtOffset<const PairValueRecord> (record, record_size);
+    }
+    return false;
+  }
+
+  void collect_glyphs (hb_collect_glyphs_context_t *c,
+                       const ValueFormat *valueFormats) const
+  {
+    unsigned int len1 = valueFormats[0].get_len ();
+    unsigned int len2 = valueFormats[1].get_len ();
+    unsigned int record_size = HBUINT16::static_size * (1 + len1 + len2);
+
+    const PairValueRecord *record = &firstPairValueRecord;
+    c->input->add_array (&record->secondGlyph, len, record_size);
+  }
+
+  void collect_variation_indices (hb_collect_variation_indices_context_t *c,
+                                  const ValueFormat *valueFormats) const
+  {
+    unsigned len1 = valueFormats[0].get_len ();
+    unsigned len2 = valueFormats[1].get_len ();
+    unsigned record_size = HBUINT16::static_size * (1 + len1 + len2);
+
+    const PairValueRecord *record = &firstPairValueRecord;
+    unsigned count = len;
+    for (unsigned i = 0; i < count; i++)
+    {
+      if (c->glyph_set->has (record->secondGlyph))
+      { record->collect_variation_indices (c, valueFormats, this); }
+
+      record = &StructAtOffset<const PairValueRecord> (record, record_size);
+    }
+  }
+
+  bool apply (hb_ot_apply_context_t *c,
+              const ValueFormat *valueFormats,
+              unsigned int pos) const
+  {
+    TRACE_APPLY (this);
+    hb_buffer_t *buffer = c->buffer;
+    unsigned int len1 = valueFormats[0].get_len ();
+    unsigned int len2 = valueFormats[1].get_len ();
+    unsigned int record_size = HBUINT16::static_size * (1 + len1 + len2);
+
+    const PairValueRecord *record = hb_bsearch (buffer->info[pos].codepoint,
+                                                &firstPairValueRecord,
+                                                len,
+                                                record_size);
+    if (record)
+    {
+      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
+      {
+	c->buffer->message (c->font,
+			    "try kerning glyphs at %d,%d",
+			    c->buffer->idx, pos);
+      }
+
+      bool applied_first = valueFormats[0].apply_value (c, this, &record->values[0], buffer->cur_pos());
+      bool applied_second = valueFormats[1].apply_value (c, this, &record->values[len1], buffer->pos[pos]);
+
+      if (applied_first || applied_second)
+	if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
+	{
+	  c->buffer->message (c->font,
+			      "kerned glyphs at %d,%d",
+			      c->buffer->idx, pos);
+	}
+
+      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())
+      {
+	c->buffer->message (c->font,
+			    "tried kerning glyphs at %d,%d",
+			    c->buffer->idx, pos);
+      }
+
+      if (applied_first || applied_second)
+        buffer->unsafe_to_break (buffer->idx, pos + 1);
+
+      if (len2)
+      {
+	pos++;
+      // https://github.com/harfbuzz/harfbuzz/issues/3824
+      // https://github.com/harfbuzz/harfbuzz/issues/3888#issuecomment-1326781116
+      buffer->unsafe_to_break (buffer->idx, pos + 1);
+      }
+
+      buffer->idx = pos;
+      return_trace (true);
+    }
+    buffer->unsafe_to_concat (buffer->idx, pos + 1);
+    return_trace (false);
+  }
+
+  bool subset (hb_subset_context_t *c,
+               const ValueFormat valueFormats[2],
+               const ValueFormat newFormats[2]) const
+  {
+    TRACE_SUBSET (this);
+    auto snap = c->serializer->snapshot ();
+
+    auto *out = c->serializer->start_embed (*this);
+    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+    out->len = 0;
+
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+    unsigned len1 = valueFormats[0].get_len ();
+    unsigned len2 = valueFormats[1].get_len ();
+    unsigned record_size = HBUINT16::static_size + Value::static_size * (len1 + len2);
+
+    typename PairValueRecord::context_t context =
+    {
+      this,
+      valueFormats,
+      newFormats,
+      len1,
+      &glyph_map,
+      c->plan->layout_variation_idx_delta_map
+    };
+
+    const PairValueRecord *record = &firstPairValueRecord;
+    unsigned count = len, num = 0;
+    for (unsigned i = 0; i < count; i++)
+    {
+      if (glyphset.has (record->secondGlyph)
+         && record->subset (c, &context)) num++;
+      record = &StructAtOffset<const PairValueRecord> (record, record_size);
+    }
+
+    out->len = num;
+    if (!num) c->serializer->revert (snap);
+    return_trace (num);
+  }
+};
+
+
+}
+}
+}
+
+#endif  // OT_LAYOUT_GPOS_PAIRSET_HH