From a92bc67f99b3c5c553e10f6d7e684f491e24dbf9 Mon Sep 17 00:00:00 2001
From: Bart Louwers <bart@emeel.net>
Date: Tue, 5 Dec 2023 14:42:48 +0100
Subject: [PATCH] Fix order_independent_hash on 32-bit platforms (#1914)

---
 src/mbgl/util/hash.hpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/mbgl/util/hash.hpp b/src/mbgl/util/hash.hpp
index e49f73cf3..2786d8d46 100644
--- a/src/mbgl/util/hash.hpp
+++ b/src/mbgl/util/hash.hpp
@@ -25,10 +25,17 @@ template <typename TIter>
 using TIterVal = std::enable_if_t<std::is_integral<typename TIter::value_type>::value, typename TIter::value_type>;
 } // namespace detail
 
+template <typename T>
+constexpr T factor() {
+    // Default factor prime value from 64-bit FNV hash.
+    if constexpr (sizeof(T) == 8) return 1099511628211;
+    // for 32-bit hash
+    return 16777619;
+}
+
 /// Generate a hash key from a collection of integer values which doesn't depend on their order.
 /// Adapted from https://stackoverflow.com/a/76993810/135138
-/// Default factor prime value from 64-bit FNV hash.
-template <typename TIter, typename TKey = detail::TIterVal<TIter>, TKey factor = 1099511628211LL>
+template <typename TIter, typename TKey = detail::TIterVal<TIter>, TKey factor = factor<TKey>()>
 TKey order_independent_hash(TIter cur, const TIter end) {
     detail::TIterVal<TIter> sum = 0, product = 1;
     for (; cur != end; ++cur) {