From f77ad4750f6594a3d717cf34424089756c745c60 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Wed, 8 Feb 2023 12:06:48 -0800
Subject: [PATCH 1/2] Add test of integer128 to_value

---
 tests/test.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tests/test.rs b/tests/test.rs
index c2050724b..f62a545e7 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -2180,6 +2180,27 @@ fn test_integer128() {
     ]);
 }
 
+#[test]
+fn test_integer128_to_value() {
+    let signed = &[i128::from(i64::min_value()), i128::from(u64::max_value())];
+    let unsigned = &[0, u128::from(u64::max_value())];
+
+    for integer128 in signed {
+        let expected = integer128.to_string();
+        assert_eq!(to_value(integer128).unwrap().to_string(), expected);
+    }
+
+    for integer128 in unsigned {
+        let expected = integer128.to_string();
+        assert_eq!(to_value(integer128).unwrap().to_string(), expected);
+    }
+
+    if !cfg!(feature = "arbitrary_precision") {
+        let err = to_value(u128::from(u64::max_value()) + 1).unwrap_err();
+        assert_eq!(err.to_string(), "number out of range");
+    }
+}
+
 #[cfg(feature = "raw_value")]
 #[test]
 fn test_borrowed_raw_value() {

From e3d13cd61aeacd28bacc4b86af45dc454e57549a Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Wed, 8 Feb 2023 12:15:07 -0800
Subject: [PATCH 2/2] Support 128-bit integers in to_value

---
 src/value/ser.rs | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/value/ser.rs b/src/value/ser.rs
index 892a63d5f..a29814e92 100644
--- a/src/value/ser.rs
+++ b/src/value/ser.rs
@@ -5,6 +5,8 @@ use crate::value::{to_value, Value};
 use alloc::borrow::ToOwned;
 use alloc::string::{String, ToString};
 use alloc::vec::Vec;
+#[cfg(not(feature = "arbitrary_precision"))]
+use core::convert::TryFrom;
 use core::fmt::Display;
 use core::result;
 use serde::ser::{Impossible, Serialize};
@@ -92,9 +94,22 @@ impl serde::Serializer for Serializer {
         Ok(Value::Number(value.into()))
     }
 
-    #[cfg(feature = "arbitrary_precision")]
     fn serialize_i128(self, value: i128) -> Result<Value> {
-        Ok(Value::Number(value.into()))
+        #[cfg(feature = "arbitrary_precision")]
+        {
+            Ok(Value::Number(value.into()))
+        }
+
+        #[cfg(not(feature = "arbitrary_precision"))]
+        {
+            if let Ok(value) = u64::try_from(value) {
+                Ok(Value::Number(value.into()))
+            } else if let Ok(value) = i64::try_from(value) {
+                Ok(Value::Number(value.into()))
+            } else {
+                Err(Error::syntax(ErrorCode::NumberOutOfRange, 0, 0))
+            }
+        }
     }
 
     #[inline]
@@ -117,9 +132,20 @@ impl serde::Serializer for Serializer {
         Ok(Value::Number(value.into()))
     }
 
-    #[cfg(feature = "arbitrary_precision")]
     fn serialize_u128(self, value: u128) -> Result<Value> {
-        Ok(Value::Number(value.into()))
+        #[cfg(feature = "arbitrary_precision")]
+        {
+            Ok(Value::Number(value.into()))
+        }
+
+        #[cfg(not(feature = "arbitrary_precision"))]
+        {
+            if let Ok(value) = u64::try_from(value) {
+                Ok(Value::Number(value.into()))
+            } else {
+                Err(Error::syntax(ErrorCode::NumberOutOfRange, 0, 0))
+            }
+        }
     }
 
     #[inline]