# net/http: 头部字段"X-Custom-Header"的值无效

- **ID:** `go/http-header-value-invalid`
- **领域:** go
- **类别:** runtime_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

头部值包含HTTP规范不允许的字符（如换行、控制字符），导致WriteHeader失败。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.21 | active | — | — |

## 解决方案

1. **** (90% 成功率)
   ```
   Use httpguts.ValidHeaderFieldValue to validate before setting
   ```
2. **** (85% 成功率)
   ```
   Sanitize input by stripping invalid characters: strings.Map(func(r rune) rune { if r < 32 || r > 126 { return -1 }; return r }, val)
   ```

## 无效尝试

- **** — Escaping may change semantics; proper sanitization needed (60% 失败率)
- **** — May break client expectations if header is required (40% 失败率)