From bd969b455203730c2e4a0f142719dda760a54cc4 Mon Sep 17 00:00:00 2001
From: pjh456 <147148383@qq.com>
Date: Fri, 9 Oct 2026 10:23:01 +0000
Subject: [PATCH] =?UTF-8?q?feat:=20substr=20=E6=98=BE=E5=BC=8F=20undefined?=
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---
 Cargo.lock                                | 38 +++++++++++------------
 Cargo.toml                                |  2 +-
 crates/oxide_builtins/src/string/basic.rs | 11 +++++--
 3 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 92cb6d61..7d5beeeb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1226,7 +1226,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1235,7 +1235,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1255,7 +1255,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1269,7 +1269,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1284,7 +1284,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1296,7 +1296,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1305,7 +1305,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1319,7 +1319,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1331,7 +1331,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1340,7 +1340,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_parser"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1355,7 +1355,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1371,7 +1371,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1384,7 +1384,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1402,7 +1402,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1415,7 +1415,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.8.98"
+version = "0.8.99"
 dependencies = [
  "bumpalo",
  "chrono",
diff --git a/Cargo.toml b/Cargo.toml
index 55766950..8755effe 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.8.98"
+version = "0.8.99"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"
diff --git a/crates/oxide_builtins/src/string/basic.rs b/crates/oxide_builtins/src/string/basic.rs
index 6eb759a3..c2998fd0 100644
--- a/crates/oxide_builtins/src/string/basic.rs
+++ b/crates/oxide_builtins/src/string/basic.rs
@@ -555,14 +555,21 @@ pub fn string_substr<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
         }
         None => 0,
     };
-    // length：负 → 0；+Inf 取剩余全部。
+    // length：显式 undefined → 剩余全部（规范步 8，ToIntegerOrInfinity 会把
+    // NaN 归零，无法区分显式 undefined 与 NaN，须先判值形态）；其余经
+    // ToIntegerOrInfinity 传播式，负/NaN → 0、+Inf → 剩余全部，夹到剩余。
     let length = match length_arg {
+        Some(v) if v.is_undefined() => len - start,
         Some(v) => {
             let p = match to_integer_or_infinity_bounded(vm, v) {
                 Ok(p) => p,
                 Err(exc) => return NativeResult::Err(exc),
             };
-            p.max(0.0) as usize
+            if p > 0.0 && p.is_infinite() {
+                len - start
+            } else {
+                p.max(0.0) as usize
+            }
         }
         None => len - start,
     };