From a58bbe5408b76c6b22d3b097649b7eef530c3e13 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 9 May 2023 12:06:35 -0600
Subject: [PATCH] [set] Use better hash

---
 src/hb-bit-page.hh | 5 +----
 src/hb-bit-set.hh  | 6 +++++-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/hb-bit-page.hh b/src/hb-bit-page.hh
index 9b027ac59..e578d2643 100644
--- a/src/hb-bit-page.hh
+++ b/src/hb-bit-page.hh
@@ -104,10 +104,7 @@ struct hb_bit_page_t
   }
   uint32_t hash () const
   {
-    return
-    + hb_iter (v)
-    | hb_reduce ([] (uint32_t h, const elt_t &_) { return h * 31 + hb_hash (_); }, (uint32_t) 0u)
-    ;
+    return hb_bytes_t ((const char *) &v, sizeof (v)).hash ();
   }
 
   void add (hb_codepoint_t g) { elt (g) |= mask (g); }
diff --git a/src/hb-bit-set.hh b/src/hb-bit-set.hh
index d290f6114..aad81e25a 100644
--- a/src/hb-bit-set.hh
+++ b/src/hb-bit-set.hh
@@ -134,7 +134,11 @@ struct hb_bit_set_t
   {
     uint32_t h = 0;
     for (auto &map : page_map)
-      h = h * 31 + hb_hash (map.major) + hb_hash (pages[map.index]);
+    {
+      auto &page = pages.arrayZ[map.index];
+      if (unlikely (page.is_empty ())) continue;
+      h = h * 31 + hb_hash (map.major) + hb_hash (page);
+    }
     return h;
   }