[bigsongeth]

User description

问题

preferences.json 走严格反序列化：容器级 #[serde(default)] 能容忍「缺字段」（老文件读新版本 OK），但扛不住「字段仍在、值非法」——当某次版本更新改了 prefs 的 schema（如重命名枚举变体、改字段类型），老用户文件里的旧值在新版本里不再合法，整份 UserPreferences 解析失败 → 旧代码 unwrap_or_else(default) 静默回落默认值，用户随手改一项就把历史设置（热键、模型选择、风格…）永久覆盖成默认。

改动

read_preferences 严格解析失败时，不再静默重置，而是：

1. 原样备份坏文件为 preferences.corrupt-<ts>.json，永不销毁；
2. 逐字段抢救（UserPreferences::salvage_from_json_bytes）——把 JSON 当对象逐 key 试解析，只把值非法的字段回默认，其余仍合法的设置全部保留；
3. 写回抢救结果，得到干净可解析的文件。

新增测试 salvage_preserves_valid_fields_when_one_value_is_invalid：构造 defaultMode 非法但 dictationHotkey / activeAsrProvider 合法的文件，断言严格解析必失败、抢救后热键与 ASR 保住、仅非法字段回默认。

适用性

面向任何跨 schema 变更升级的用户，不局限于某种安装方式——只要某次发布改了 prefs 结构，此改动就能避免老用户设置被整份清空。维护者若认为发布流程已通过 serde default 覆盖此风险，可自行取舍。

Co-Authored-By: Claude Opus 4.8 noreply@anthropic.com

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PR Type

Bug fix, Enhancement

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Description

• Backup corrupt preferences.json before salvage

• Per-field rescue: keep valid values, drop only invalid ones

• Write back salvaged file to avoid silent setting loss

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Diagram Walkthrough

flowchart LR
  A["Strict decode fails"] --> B["Backup original file"]
  B --> C["Parse JSON as Value"]
  C --> D{Is object?}
  D -- yes --> E["Normalize aliases"]
  E --> F["For each field, test validity"]
  F --> G["Keep valid fields, drop invalid"]
  G --> H["Re-serialize and write back"]
  H --> I["Return salvaged UserPreferences"]
  D -- no --> J["Use defaults"]

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File Walkthrough

Relevant files

Enhancement

preferences.rs Backup & salvage corrupt preferences on parse failure        openless-all/app/src-tauri/src/persistence/preferences.rs On strict parse failure, backup original file instead of silently resetting Add backup_unparseable_preferences for atomic backup with unique name Salvage valid fields using UserPreferences::salvage_from_json_bytes Write back salvaged preferences to avoid future decode failures +133/-17 types.rs Add per-field salvage logic for UserPreferences                    openless-all/app/src-tauri/src/types.rs Implement UserPreferences::salvage_from_json_bytes for per-field rescue Add preference_field_is_valid to test individual field validity Add normalize_preference_aliases to handle duplicate legacy keys Add salvage_without_incomplete_legacy_hotkey for edge cases Include unit tests verifying field preservation and alias handling +175/-0

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[github-actions]

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(Review updated until commit eac5af5)

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[github-actions]

Persistent review updated to latest commit eac5af5