fix: preserve property defaults and Emacs 31 compatibility

.gitignore

@@ -5,3 +5,4 @@ archive
 *.o
 *.elc
 AGENTS.md
+!AGENTS.md

.phrase/docs/CHANGE.md

@@ -2,6 +2,13 @@
 
 ## phase-kp-overhaul-20260726
 
+- 2026-09-01 restore Emacs 31.1 strict byte compilation without behavior
+  changes (`task044`, `issue029`):
+  `.phrase/phases/phase-kp-overhaul-20260726/change_post_audit_hardening_20260820.md`
+- 2026-08-31 restore the Emacs 31 fresh-source baseline while preserving
+  multibyte policy ownership and real-buffer marker noninheritance
+  (`task043`):
+  `.phrase/phases/phase-kp-overhaul-20260726/change_post_audit_hardening_20260820.md`
 - 2026-08-20 plan and implement post-audit hardening (`task037`–`task042`,
   `task030` source-fresh evaluator continuation; `issue022`–`issue028`):
   `.phrase/phases/phase-kp-overhaul-20260726/change_post_audit_hardening_20260820.md`

.phrase/docs/ISSUES.md

@@ -28,3 +28,4 @@
 - issue026 [ ] [Showcase loses automatic inline policy and test runners can false-green.](../phases/phase-kp-overhaul-20260726/issue_showcase_test_freshness_20260820.md)
 - issue027 [x] [Manual integrations remain installed with no projection owner.](../phases/phase-kp-overhaul-20260726/issue_integration_no_projection_20260820.md)
 - issue028 [x] [Locked live evaluator can measure stale candidate bytecode.](../phases/phase-kp-overhaul-20260726/issue_live_evaluator_source_freshness_20260820.md)
+- issue029 [x] [Emacs 31.1 WERROR rejects obsolete single-binding let macros.](../phases/phase-kp-overhaul-20260726/issue_emacs31_strict_compile_20260901.md)

.phrase/phases/phase-kp-overhaul-20260726/change_post_audit_hardening_20260820.md

@@ -1,5 +1,38 @@
 # Change: Post-Audit Hardening 2026-08-20
 
+## 2026-09-01 — Restore Emacs 31.1 strict byte compilation
+
+- **Modify** `ekp.el`, `ekp-utils.el`, and `ekp-hyphen.el` by replacing six
+  obsolete single-binding `if-let`/`when-let` forms with the behavior-identical
+  starred variants.
+- **Modify** `tests/ekp-live-commit-evaluator.el` in the same mechanical way so
+  maintained performance tooling is strict-compile clean too.
+- **Add** `issue029` and close `task044` with exact environment and evidence.
+- **Behavior/Risk:** no data flow, branch, public API, layout, hyphenation,
+  font, module-path, or evaluator behavior changes.
+- **Evidence:** root `make`; Emacs 31.1 WERROR production and changed-tool
+  compilation; normal and seed-20260901 random ERT 296/296; C build; 300-case
+  parity fuzz; release invariants; local 49-entry dictionary manifest/hash;
+  checkdoc; and diff-check. The user explicitly excluded the network-backed
+  fixed-upstream dictionary fetch, so it is not claimed.
+
+## 2026-08-31 — Restore the Emacs 31 fresh-source baseline
+
+- **Modify** `ekp.el` and `ekp-buffer.el` so layout and projection marker
+  properties update the toplevel default of Emacs 31's automatically
+  buffer-local `text-property-default-nonsticky`; new and existing buffers
+  that have no explicit override now inherit the nonsticky protocol.
+- **Modify** `tests/ekp-tests.el` and `tests/ekp-buffer-tests.el` so policy
+  ownership fixtures remain mutable multibyte strings while mutating ASCII
+  code points that Emacs 31 permits in place. The tests still prove that
+  cache keys own the original policy values.
+- **Behavior/Risk:** no layout algorithm or public policy changes. This fixes
+  marker noninheritance in real buffers and removes an Emacs 31-only fixture
+  mutation error.
+- **Evidence:** focused ERT 3/3; source-first normal and seed-20260831 random
+  ERT 296/296; source load, release invariants, 49-entry dictionary manifest,
+  and pinned dictionary update checks pass.
+
 ## 2026-08-20 — Lock follow-up goals and task boundaries
 
 - **Add** `plan_post_audit_hardening_20260820.md` with the evidence-backed

.phrase/phases/phase-kp-overhaul-20260726/issue_emacs31_strict_compile_20260901.md

@@ -0,0 +1,44 @@
+# issue029 — Emacs 31.1 strict compilation rejects obsolete let macros
+
+Status: resolved
+
+## Environment
+
+- GNU Emacs 31.1 development build `fac653279dcb`
+- macOS Apple Silicon
+- EKP HEAD `97cb6a6e3506`
+
+## Reproduction
+
+Run the repository CI byte-compilation command with
+`byte-compile-error-on-warn` set to `t` against the four production files.
+
+## Expected vs actual
+
+- Expected: production and maintained test tools compile with warnings treated
+  as errors on the recorded Emacs executable.
+- Actual: Emacs 31.1 rejects six single-binding `if-let`/`when-let` forms in
+  production; strict changed-tool compilation also finds three such forms in
+  `tests/ekp-live-commit-evaluator.el`.
+
+## Investigation and fix
+
+The macros became obsolete in Emacs 31.1. Every affected form has exactly one
+binding, so the starred replacement has identical binding, truth, body, and
+fallback behavior and needs no compatibility branch. Replace only those nine
+macro names; do not alter layout or evaluator data flow.
+
+## Verification
+
+`task044` passed root integration compilation; WERROR production and changed
+evaluator compilation; normal and seed-20260901 random ERT 296/296; warning-clean
+C build; 300-case C/Elisp parity fuzz; release invariants; local 49-entry
+dictionary manifest/hash; checkdoc; and diff-check. The network-backed
+fixed-upstream dictionary fetch was stopped and excluded at the user's explicit
+direction; no upstream-provenance claim is made.
+
+Resolved At: 2026-09-01
+
+Resolved By: C1a nine-repository verification
+
+Commit: pending (protected pre-existing dirty worktree)

.phrase/phases/phase-kp-overhaul-20260726/plan_post_audit_hardening_20260820.md

@@ -80,3 +80,15 @@ Stop only when all tasks in this plan have current issue/task evidence,
 closed issues have user-visible or contract-level verification, `issue018`
 is either genuinely closed by its locked gate or explicitly remains open with
 fresh measurements, and the complete diff is committed and reviewed.
+
+## 2026-09-01 Emacs 31 strict-compile follow-up
+
+- `task044` / `issue029` replace the six remaining single-binding
+  `if-let`/`when-let` forms in production and the three forms in the live
+  evaluator with their semantically identical starred variants.
+- No layout, hyphenation, font-selection, module-path, or evaluator behavior
+  may change. Existing ERT coverage locks those paths; Emacs 31.1 WERROR byte
+  compilation is the regression gate for the compatibility defect itself.
+- Closure requires root integration compilation, strict production and changed
+  test-tool compilation, the complete normal and seeded-random ERT suites, C
+  build/parity fuzz, release/dictionary checks, checkdoc, and diff-check.

.phrase/phases/phase-kp-overhaul-20260726/task_post_audit_hardening_20260820.md

@@ -1,5 +1,23 @@
 # Tasks: Post-Audit Hardening 2026-08-20
 
+- task044 [x] Restore Emacs 31.1 WERROR compilation by replacing obsolete
+  single-binding `if-let`/`when-let` forms with behavior-identical
+  `if-let*`/`when-let*` forms in production and the live evaluator.
+  - Source: `issue029` and the C1a nine-repository strict-compile gate.
+  - Validation: root `make`; Emacs 31.1 WERROR production and changed-tool
+    compilation; normal/random ERT 296/296; C build and 300-case fuzz;
+    release, local 49-entry dictionary manifest/hash, checkdoc, and diff gates.
+    The network-backed fixed-upstream dictionary fetch was explicitly excluded
+    by the user and is not claimed as evidence.
+
+- task043 [x] Restore the Emacs 31 fresh-source baseline without weakening
+  cache-ownership or marker-noninheritance contracts. Keep policy fixtures
+  mutable and multibyte, and install EKP marker properties in the global
+  `text-property-default-nonsticky` default used by real buffers.
+  - Source: Emacs 31 fresh-source failures in the M0a baseline.
+  - Validation: focused ERT 3/3, normal and seeded-random ERT 296/296,
+    source-load, release, and 49-entry dictionary gates.
+
 - task037 [x] Validate public buffer widths before mutation and make rejected
   `ekp-justify-region` requests failure-atomic. Add red tests for zero,
   negative, non-integer, and projection-preservation cases.

AGENTS.md

@@ -0,0 +1,144 @@
+# 核心协议：意图识别（强制执行）
+
+在处理任何请求之前，你必须先识别用户的意图并遵循相应的协议。
+
+## 1. 🌱 启动 / 立项 / 模糊想法
+**触发条件**：用户想要开启新项目、新阶段，或者只有一个模糊的想法。
+**行动**：
+1.  **扫描**：读取 `.phrase/modules/pr_faq.md` 的 YAML 元数据以确认匹配。
+2.  **加载**：仅当匹配成功时，完整读取该文件内容。
+3.  **执行**：扮演“严格的产品经理”角色。进行访谈以起草亚马逊风格的 PR/FAQ。
+4.  **约束**：在 PR/FAQ 最终确定之前，禁止开始编写代码或拆解任务。
+
+## 2. 🔨 编码 / 重构 / 审查
+**触发条件**：用户请求代码实现、Bug 修复、重构或代码审查。
+**行动**：
+1.  **扫描**：读取 `.phrase/modules/linus_coding.md` 的 YAML 元数据以确认匹配。
+2.  **加载**：仅当匹配成功时，完整读取该文件内容。
+3.  **执行**：扮演“Linus Torvalds”角色。
+4.  **约束**：在编码前和编码过程中，严格执行“5 层思考模型”和“好品味”判断。
+
+## 3. ✍️ 文案 / 营销 / 文档
+**触发条件**：用户需要撰写 README、发布说明、产品介绍或营销文案。
+**行动**：
+1.  **扫描**：读取 `.phrase/modules/copywriting.md` 的 YAML 元数据以确认匹配。
+2.  **加载**：仅当匹配成功时，完整读取该文件内容。
+3.  **执行**：扮演“转化率文案专家”角色。
+4.  **约束**：遵循“结论先行”、“降低成本”、“可感知的具体”等 10 大原则。
+
+## 4. 🌐 浏览器 / 网页自动化 / 爬虫
+**触发条件**：用户需要访问网页、抓取数据、截图、测试 Web UI 或填写表单。
+**行动**：
+1.  **扫描**：读取 `.phrase/modules/agent-browser.md` 的 YAML 元数据以确认匹配。
+2.  **检查**：确保环境中已安装 `agent-browser` 依赖。
+3.  **加载**：仅当匹配成功且依赖满足时，完整读取该文件内容。
+4.  **执行**：使用 CLI 工具进行浏览器自动化操作。
+
+## 5. 📋 任务执行（默认）
+**触发条件**：用户想要执行一个具体的、已定义的任务。
+**行动**：遵循下方的“文档驱动开发”工作流。
+
+---
+
+“文档驱动开发（Doc-Driven Development）”：先锁定文档 →  拆 `taskNNN` → 实现与验证 → 回写文档。
+
+---
+
+## 0. 原则（按优先级）
+- 仓库既有规范 > 本文；冲突时按 `README`/`STYLEGUIDE` 等执行，并在 `issue_*`/`change_*` 记录取舍。
+- 文档为事实来源：需求、交互、接口只能来自 `spec/plan/tech-refer/adr`。
+- 单次仅处理一个原子任务；所有改动可追溯到 `taskNNN` 与其依据（`spec`/`issue`/`adr`）。
+- 每个 `taskNNN` 必须说明验证方式（测试或手动步骤）。
+- 实现完成必须回写：`task_*`、`change_*`，必要时更新 `spec_*`/`issue_*`/`adr_*`。
+
+---
+
+## 1. 仓库结构与文档
+- 代码根：`App/`, `Core/`, `UI/`, `Shared/`, `Tests/`, `Assets/`, `Samples/`, `Schemas/`, `StackWM-Bridging-Header.h`。保持分层清晰，`Tests/` 镜像核心模块。
+- 文档根：`.phrase/`
+  - 阶段：`.phrase/phases/phase-<purpose>-<YYYYMMDD>/`
+  - 全局索引：`.phrase/docs/`
+- `Docs/` 为外部文档，可继续独立存放。
+
+---
+
+## 2. Phase 工作流
+1. **Phase Gate**（仅当用户明确开启新阶段）：在新 `phase-*` 目录创建最小集 `spec_*`, `plan_*`, `task_*`, 视需求补 `tech-refer_*`/`adr_*`，`issue_*` 可后置。
+2. **In-Phase Loop**（默认）：  
+   - 新需求 → 更新当前 `plan_*` → 拆 `taskNNN`。  
+   - 实现 → 在 `task_*` 中新增/更新并执行对应任务。  
+   - Bug → 在 `.phrase/docs/ISSUES.md` 登记 `issueNNN`，在 phase 写详情，再拆 `taskNNN`。  
+   - 不可逆决策 → 先写 `adr_*` 或在 `tech-refer_*` 增 “Decision”。
+3. **Task 闭环**：完成后需  
+   1) 将 `task_*` 条目标记 `[x]`  
+   2) 在 phase `change_*` 记录条目，并于 `.phrase/docs/CHANGE.md` 加索引  
+   3) 若影响交互，更新对应 `spec_*`  
+   4) 若解决问题，更新 `ISSUES.md` 和 issue 详情（含验证结论）
+
+当目标与当前 phase purpose 明显不同、需要独立里程碑或架构大重构时，可建议开启新 phase，但需用户确认。
+
+### Phase 生命周期
+- 开启阶段：在 `.phrase/phases/phase-<purpose>-<date>/` 下创建 `spec/plan/task/...`。
+- 阶段完结：用户确认后，将整个目录重命名为 `DONE-phase-<purpose>-<date>/`，同时把主要文档也按规则改为 `DONE-PLAN-*`、`DONE-TASK-*` 等，确保一眼可见结项状态。
+
+---
+
+## 3. Task / Issue 规范
+- `taskNNN` 为三位递增 ID（`task001` 起），不可重排或复用；拆分/合并需创建新 ID 并在原任务注明流向。
+- 任何对 `task_*` 的增删改/勾选都要在当前 phase `change_*` 记录一次，可批量合并但必须可追溯。
+- 原子任务标准：一次工作会话可完成、产出可观察、可独立验证，既不过细也不过粗。
+- Issue：
+  - 全局索引：`.phrase/docs/ISSUES.md` 用 `issueNNN [ ]/[x]` 并链接 phase 详情。
+  - 详情文件 `issue_<purpose>_<YYYYMMDD>.md` 需含环境、复现、调查、根因、修复、验证、关联的 `taskNNN`/提交。
+  - 用户可感知问题需在标记 `[x]` 前获得确认，并记录 `Resolved At/By/Commit`。
+
+---
+
+## 4. Build / Test / Dev
+- 首选仓库入口：若提供 Makefile、GitHub Actions、或 scripts/，优先使用。
+- windows系统下 emacs 路径: "C:\Users\26289\Apps\emacs-30.2\emacs-30.2\bin"
+- 常见 Elisp 验证方式：
+  - 运行 ERT 测试：emacs -Q --batch -L . -l <test-file> -f ert-run-tests-batch-and-exit
+  - 交互手动验证：emacs -Q -L . -l <pkg>.el 后在 UI 中 M-x 执行命令
+- 可选：lint/格式（按仓库约定），例如 package-lint、checkdoc、byte-compile（若项目采用）。
+- 测试用例全部写在根目录的 tests/ 目录下
+
+---
+
+## 5. 编码与验证
+- 遵循仓库已有编码规范（缩进、命名、lexical-binding 等）。
+- 明确支持的 Emacs 版本范围；涉及 API 差异时要写清楚 fallback 或条件分支策略。
+- 尽量保持改动最小化：除非任务是“清理”，否则避免批量格式化与无关重排。
+- 关键路径加可诊断日志（遵循项目 logging 方案）。
+- 测试优先覆盖核心逻辑；UI/系统胶水可提供手动验证步骤。测试必须确定性，必要时注入依赖或 mock。
+
+---
+
+## 6. 文档更新与 Changelog
+- `change_*`：phase 内的真实变更记录；每个完成的 `taskNNN` 至少一条，包含日期、文件/路径、Add|Modify|Delete、受影响函数、行为/风险说明，按时间倒序。
+- `.phrase/docs/CHANGE.md`：仅索引与摘要，指向对应 phase `change_*` 条目；可按工作会话批量更新。
+- `spec_*`/`plan_*`/`tech-refer_*`/`adr_*`/`issue_*` 均需随变更回写（增量即可），保持单一事实来源。
+
+---
+
+## 7. 提交、PR 与安全
+- 默认使用 Conventional Commits（`feat:`, `fix:`, `docs:`, `test:`, `chore:` 等），一份提交聚焦单个 `taskNNN`。
+- PR 描述需列出关联的 `taskNNN`/`issueNNN`、动机、行为变化、验证方式、风险/回滚方案，并在 UI 变化时附截图/GIF。
+- 禁止提交密钥、token、证书、真实用户数据；涉及权限/配置的任务，需在 `spec_*` 和 `tech-refer_*` 清楚描述失败反馈、API 边界与排查方式。
+
+---
+
+## 8. 模板速览
+- `spec`: Summary / Goals & Non-goals / User Flows（操作→反馈→回退）/ Edge Cases / Acceptance Criteria
+- `plan`: Milestones / Scope / Priorities / Risks & Dependencies /（可选）Rollback
+- `tech-refer`: Options / Proposed Approach / Interfaces & APIs / Trade-offs / Risks & Mitigations
+- `task`: `task001 [ ] 产出 + 验证方式 + 影响范围`
+- `issue`: `issueNNN [ ] Summary + Environment + Repro + Expected vs Actual + Investigation + Fix + Verification + User Confirmation + Resolved At/By/Commit`
+- `adr`: Context / Decision / Alternatives / Consequences / Rollback
+
+---
+
+## 9. 协作表达提示
+- 解释方案时优先描述用户操作（快捷键/鼠标/命令）、可见反馈、撤销/失败路径、边界情况。
+- 引用文档时用“文件名 + 小节”口语化说明，不逐字背诵。
+- 提供可选方案时说明它们属于当前还是后续里程碑，帮助用户决策。

ekp-buffer.el

@@ -253,7 +253,7 @@ caps the narrowest live window at N pixels."
   "Unicode whitespace that cannot use the ASCII-space projection path.")
 
 (dolist (property ekp-buffer--owned-properties)
-  (setf (alist-get property text-property-default-nonsticky) t))
+  (ekp--make-text-property-default-nonsticky property))
 
 ;;; Setup
 

ekp-hyphen.el

@@ -169,7 +169,7 @@ LANGUAGE identifies the dictionary in that condition."
                         (lambda (m) (string (string-to-number
                                              (match-string 1 m) 16)))
                         line))
-            (when-let ((parsed (ekp-hyphen--parse-pattern line)))
+            (when-let* ((parsed (ekp-hyphen--parse-pattern line)))
               (puthash (car parsed) (cdr parsed) patterns)
               (setq maxlen (max maxlen (length (car parsed))))))))
         (forward-line 1)))
@@ -227,7 +227,7 @@ by default the dictionary's own LEFTHYPHENMIN/RIGHTHYPHENMIN apply
   (let ((path (or (and lang (ekp-hyphen--resolve-lang lang)) file)))
     (unless path
       (signal 'ekp-hyphen-dictionary-not-found (list lang)))
-    (when-let ((count (gethash path ekp-hyphen--unsupported-cache)))
+    (when-let* ((count (gethash path ekp-hyphen--unsupported-cache)))
       (signal 'ekp-hyphen-unsupported-pattern
               (list (or lang path) path count)))
     (let ((h (or (gethash path ekp-hyphen--cache)

ekp-utils.el

@@ -122,7 +122,7 @@ Use the blank glyph of STRING's Latin font; for a monospace font
 that width is the space's own advance."
   ;; font is monospace, use the pixel of blank
   ;; as word spacing pixel
-  (if-let ((font-family (ekp-monospace-p string)))
+  (if-let* ((font-family (ekp-monospace-p string)))
       (ekp--measured-width
        (propertize " " 'face `(:family ,font-family)))
     (let* ((letter (ekp-get-latin-letter string))
@@ -134,14 +134,14 @@ that width is the space's own advance."
 (defun ekp-latin-font (string)
   "Return the font family used for STRING's Latin letters.
 Fall back to the default face family when STRING has no Latin letter."
-  (if-let ((letter (ekp-get-latin-letter string)))
+  (if-let* ((letter (ekp-get-latin-letter string)))
       (ekp-font-family letter)
     (face-attribute 'default :family)))
 
 (defun ekp-cjk-font (string)
   "Return the font family used for STRING's CJK characters.
 Fall back to the family of a sample CJK glyph when STRING has none."
-  (if-let ((letter (ekp-get-cjk-letter string)))
+  (if-let* ((letter (ekp-get-cjk-letter string)))
       (ekp-font-family letter)
     (ekp-font-family "牛")))
 
@@ -344,7 +344,7 @@ by merging boxes."
 
 (defun ekp-c-module-dir ()
   "Return the C module directory."
-  (when-let ((root-dir (ekp-root-dir)))
+  (when-let* ((root-dir (ekp-root-dir)))
     (expand-file-name "ekp_c" root-dir)))
 
 (defun ekp-c-module-file ()

ekp.el

@@ -1790,8 +1790,8 @@ POLICY-ANALYSIS is a precomputed result from `ekp--analyze-policies'."
       (while (and (>= tail 0) (= (aref old tail) ?\s))
         (setq tail (1- tail)))
       (when (>= tail 0)
-        (when-let ((space
+        (when-let* ((space
-                    (cl-position ?\s old :from-end t :end (1+ tail))))
+                     (cl-position ?\s old :from-end t :end (1+ tail))))
           (1+ space))))))
 
 (defun ekp--para-has-box-type-p (para type)
@@ -3606,11 +3606,19 @@ Only property-free, context-stable 1D layouts take this fast path."
   '(ekp-glue ekp-soft-break ekp-soft-hyphen ekp-hidden ekp-justified)
   "Text properties owned by the lossless render/inversion protocol.")
 
+(defun ekp--make-text-property-default-nonsticky (property)
+  "Make PROPERTY nonsticky by default in every buffer."
+  (let ((defaults (copy-tree
+                   (default-toplevel-value
+                    'text-property-default-nonsticky))))
+    (setf (alist-get property defaults) t)
+    (set-default-toplevel-value 'text-property-default-nonsticky defaults)))
+
 ;; Text typed next to a marker character must never inherit the
 ;; marker: a self-inserted char inheriting `ekp-glue' would be treated
 ;; as a synthesized space by the next unjustification and deleted.
 (dolist (prop ekp--layout-marker-properties)
-  (setf (alist-get prop text-property-default-nonsticky) t))
+  (ekp--make-text-property-default-nonsticky prop))
 
 (defun ekp--hide-string (string)
   "Return STRING marked `ekp-hidden' and displayed as nothing."

tests/ekp-buffer-tests.el

@@ -3481,8 +3481,8 @@ a zero budget still makes progress (exactly one chunk)."
   (ekp-buffer-test--with-text ""
     (text-mode)
     (let* ((ekp-use-c-module nil)
-           (suffix (copy-sequence "uX"))
+           (suffix (copy-sequence (string-as-multibyte "uX")))
-           (line-start-extra (copy-sequence "《"))
+           (line-start-extra (copy-sequence "《X"))
            (ekp-number-unit-suffixes (list suffix))
            (ekp-token-break-policies '((number-unit . no-break)))
            (ekp-kinsoku-profile 'custom)
@@ -3499,18 +3499,20 @@ a zero budget still makes progress (exactly one chunk)."
                    (apply original arguments))))
         (setq first (cdr (ekp-buffer--live-plan-entry text width)))
         (setq key (caar ekp-buffer--live-plan-cache))
+        (should (multibyte-string-p suffix))
+        (should (multibyte-string-p line-start-extra))
         (should (seq-some (lambda (string) (equal string "uX"))
                           (ekp-buffer-test--strings-in-tree key)))
-        (should (seq-some (lambda (string) (equal string "《"))
+        (should (seq-some (lambda (string) (equal string "《X"))
                           (ekp-buffer-test--strings-in-tree key)))
         (store-substring suffix 1 "Y")
-        (store-substring line-start-extra 0 "》")
+        (store-substring line-start-extra 1 "Y")
         (let ((changed (cdr (ekp-buffer--live-plan-entry text width))))
           (should-not (eq changed first))
           (should (= calls 2)))
         (should (seq-some (lambda (string) (equal string "uX"))
                           (ekp-buffer-test--strings-in-tree key)))
-        (should (seq-some (lambda (string) (equal string "《"))
+        (should (seq-some (lambda (string) (equal string "《X"))
                           (ekp-buffer-test--strings-in-tree key)))))))
 
 (provide 'ekp-buffer-tests)

tests/ekp-live-commit-evaluator.el

@@ -71,19 +71,19 @@
 
 (defun ekp-live-commit-evaluator--env-number (name fallback)
   "Return numeric environment variable NAME, or FALLBACK."
-  (if-let ((value (getenv name)))
+  (if-let* ((value (getenv name)))
       (string-to-number value)
     fallback))
 
 (defun ekp-live-commit-evaluator--env-numbers (name fallback)
   "Return comma-separated numeric environment variable NAME, or FALLBACK."
-  (if-let ((value (getenv name)))
+  (if-let* ((value (getenv name)))
       (mapcar #'string-to-number (split-string value "," t "[ \t]+"))
     fallback))
 
 (defun ekp-live-commit-evaluator--env-strings (name fallback)
   "Return comma-separated string environment variable NAME, or FALLBACK."
-  (if-let ((value (getenv name)))
+  (if-let* ((value (getenv name)))
       (split-string value "," t "[ \t]+")
     fallback))
 

tests/ekp-tests.el

@@ -2052,7 +2052,13 @@ module is bypassed automatically (it has no looseness support)."
                  '(ekp-glue ekp-soft-break ekp-soft-hyphen ekp-hidden
                    ekp-justified)))
   (dolist (property ekp--layout-marker-properties)
-    (should (eq (alist-get property text-property-default-nonsticky) t))))
+    (should
+     (eq (alist-get property
+                    (default-value 'text-property-default-nonsticky))
+         t))
+    (with-temp-buffer
+      (should
+       (eq (alist-get property text-property-default-nonsticky) t)))))
 
 (ert-deftest ekp-test-layout-plan-maps-source-gaps-and-breaks ()
   "The semantic plan must retain source offsets for every visual decision."
@@ -2813,8 +2819,8 @@ returned the stale looseness-0 layout for the same (string, width)."
   "Policy-analysis cache keys must own mutable public policy strings."
   (ekp-tests--with-clean-state
    (let* ((ekp-use-c-module nil)
-          (suffix (copy-sequence "uX"))
+          (suffix (copy-sequence (string-as-multibyte "uX")))
-          (line-start-extra (copy-sequence "《"))
+          (line-start-extra (copy-sequence "《X"))
           (ekp-number-unit-suffixes (list suffix))
           (ekp-token-break-policies '((number-unit . no-break)))
           (ekp-kinsoku-profile 'custom)
@@ -2823,6 +2829,8 @@ returned the stale looseness-0 layout for the same (string, width)."
           (width 16)
           cache-key first-plan)
      (setq first-plan (ekp-layout-plan text width))
+     (should (multibyte-string-p suffix))
+     (should (multibyte-string-p line-start-extra))
      (should
       (seq-some
        (lambda (interval)
@@ -2835,13 +2843,13 @@ returned the stale looseness-0 layout for the same (string, width)."
      (should cache-key)
      (should (seq-some (lambda (string) (equal string "uX"))
                        (ekp-tests--strings-in-tree cache-key)))
-     (should (seq-some (lambda (string) (equal string "《"))
+     (should (seq-some (lambda (string) (equal string "《X"))
                        (ekp-tests--strings-in-tree cache-key)))
      (store-substring suffix 1 "Y")
-     (store-substring line-start-extra 0 "》")
+     (store-substring line-start-extra 1 "Y")
      (should (seq-some (lambda (string) (equal string "uX"))
                        (ekp-tests--strings-in-tree cache-key)))
-     (should (seq-some (lambda (string) (equal string "《"))
+     (should (seq-some (lambda (string) (equal string "《X"))
                        (ekp-tests--strings-in-tree cache-key)))
      (let ((changed-plan (ekp-layout-plan text width)))
        (should-not