From 16679d30668e2d5d33de9b24425a33ea4102adad Mon Sep 17 00:00:00 2001
From: Federicorao <157750791+Federicorao@users.noreply.github.com>
Date: Fri, 12 Jun 2026 12:04:25 +0000
Subject: [PATCH 1/2] Honor int_max_str_digits in native JSON scanner

Route native _json integer parsing through bytes_to_int with the live VM digit limit, matching int() and the pure-Python JSON path. Add snippet coverage for the boundary.

Assisted-by: OpenAI GPT-5:gpt-5
---
 crates/stdlib/src/json.rs           | 12 ++++++++----
 extra_tests/snippets/stdlib_json.py | 14 ++++++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/crates/stdlib/src/json.rs b/crates/stdlib/src/json.rs
index dc2fbbc8892..2ba6c11f330 100644
--- a/crates/stdlib/src/json.rs
+++ b/crates/stdlib/src/json.rs
@@ -9,12 +9,11 @@ mod _json {
         builtins::{PyBaseExceptionRef, PyStrRef, PyType},
         convert::ToPyResult,
         function::{IntoFuncArgs, OptionalArg},
-        protocol::PyIterReturn,
+        protocol::{handle_bytes_to_int_err, PyIterReturn},
         types::{Callable, Constructor},
     };
     use core::str::FromStr;
-    use malachite_bigint::BigInt;
-    use rustpython_common::wtf8::Wtf8Buf;
+    use rustpython_common::{int::bytes_to_int, wtf8::Wtf8Buf};
     use std::collections::HashMap;
 
     /// Skip JSON whitespace characters (space, tab, newline, carriage return).
@@ -243,7 +242,12 @@ mod _json {
             } else if let Some(ref parse_int) = self.parse_int {
                 parse_int.call((buf,), vm)
             } else {
-                Ok(vm.new_pyobj(BigInt::from_str(buf).unwrap()))
+                let value = bytes_to_int(buf.as_bytes(), 10, vm.state.int_max_str_digits.load())
+                    .map_err(|e| {
+                        let obj = vm.ctx.new_str(buf);
+                        handle_bytes_to_int_err(e, obj.as_object(), vm)
+                    })?;
+                Ok(vm.new_pyobj(value))
             };
             Some((ret, buf.len()))
         }
diff --git a/extra_tests/snippets/stdlib_json.py b/extra_tests/snippets/stdlib_json.py
index e55382c8223..5237cc67453 100644
--- a/extra_tests/snippets/stdlib_json.py
+++ b/extra_tests/snippets/stdlib_json.py
@@ -261,3 +261,17 @@ def assert_no_native_stack_overflow(func):
     assert e.pos == 5, f"expected pos=5, got {e.pos}"
 else:
     raise AssertionError("expected JSONDecodeError")
+
+# Test that json.loads honors sys.int_max_str_digits
+import sys
+
+_min_limit = sys.int_info.str_digits_check_threshold
+_orig_limit = sys.get_int_max_str_digits()
+try:
+    sys.set_int_max_str_digits(_min_limit)
+    with assert_raises(ValueError):
+        json.loads("1" * (_min_limit + 1))
+    assert json.loads("1" * _min_limit) == int("1" * _min_limit)
+    assert json.loads('42') == 42
+finally:
+    sys.set_int_max_str_digits(_orig_limit)

From 2707f543e05a0106ab7ea291dbe9ae50d0699a09 Mon Sep 17 00:00:00 2001
From: Federicorao <raofederico3@gmail.com>
Date: Thu, 18 Jun 2026 12:31:38 +0200
Subject: [PATCH 2/2] Fix JSON int limit CI failures

---
 crates/stdlib/src/json.rs           | 6 +++---
 extra_tests/snippets/stdlib_json.py | 3 +--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/crates/stdlib/src/json.rs b/crates/stdlib/src/json.rs
index 2ba6c11f330..37691d2b926 100644
--- a/crates/stdlib/src/json.rs
+++ b/crates/stdlib/src/json.rs
@@ -242,12 +242,12 @@ mod _json {
             } else if let Some(ref parse_int) = self.parse_int {
                 parse_int.call((buf,), vm)
             } else {
-                let value = bytes_to_int(buf.as_bytes(), 10, vm.state.int_max_str_digits.load())
+                bytes_to_int(buf.as_bytes(), 10, vm.state.int_max_str_digits.load())
+                    .map(|value| vm.new_pyobj(value))
                     .map_err(|e| {
                         let obj = vm.ctx.new_str(buf);
                         handle_bytes_to_int_err(e, obj.as_object(), vm)
-                    })?;
-                Ok(vm.new_pyobj(value))
+                    })
             };
             Some((ret, buf.len()))
         }
diff --git a/extra_tests/snippets/stdlib_json.py b/extra_tests/snippets/stdlib_json.py
index 5237cc67453..406476ae8c6 100644
--- a/extra_tests/snippets/stdlib_json.py
+++ b/extra_tests/snippets/stdlib_json.py
@@ -1,4 +1,5 @@
 import json
+import sys
 from io import BytesIO, StringIO
 
 from testutils import assert_raises
@@ -263,8 +264,6 @@ def assert_no_native_stack_overflow(func):
     raise AssertionError("expected JSONDecodeError")
 
 # Test that json.loads honors sys.int_max_str_digits
-import sys
-
 _min_limit = sys.int_info.str_digits_check_threshold
 _orig_limit = sys.get_int_max_str_digits()
 try: