perf: coalesce viewport resize delivery

docs/user/ebox-api-reference.en.md

@@ -431,6 +431,12 @@ context. For pure rendering, callers may instead bind `ebox-viewport-width`
 in pixels and `ebox-viewport-height` in lines around the render. Do not mutate
 a published node tree in place.
 
+Visible mounted buffers follow their displaying window automatically. Ebox
+coalesces continuous size events and publishes only the latest sample after
+`ebox-viewport-resize-delay` (0.05 seconds by default).
+`ebox-viewport-window-width` returns the same display-safe pixel width used by
+that controller, so hosts must not install a second resize hook or width rule.
+
 ## 7. Selectors
 
 `ebox-selector-parse` delegates to ECSS and returns its structured AST.
@@ -516,6 +522,7 @@ The main customization variables are:
 | Lazy scroll | `ebox-scroll-lazy-prefix-lookahead-lines` 8; `ebox-scroll-lazy-idle-prefetch-lines` 128; `ebox-scroll-lazy-idle-prefetch-slice-lines` 16; `ebox-scroll-lazy-idle-prefetch-delay` 0.15 |
 | Runtime prewarm | `ebox-runtime-idle-prewarm` t; `ebox-runtime-idle-prewarm-delay` 0.1; `ebox-runtime-idle-prewarm-prefix-resume-delay` 2.0; `ebox-runtime-idle-prewarm-slice-size` 32; `ebox-native-buffer-scroll` t (initial/visible-window handoff only; strict root-owner proof) |
 | Predicted reflow | `ebox-runtime-idle-reflow-cache-prewarm` t; `ebox-runtime-idle-reflow-cache-prewarm-delay` 0.15 |
+| Viewport delivery | `ebox-viewport-resize-delay` 0.05; continuous window events replace one pending sample per mounted buffer |
 | Reflow GC | `ebox-reflow-cache-prewarm-gc-cons-threshold` `auto`; `ebox-reflow-cache-prewarm-gc-auto-frame-budget` 0.2; `ebox-reflow-cache-prewarm-gc-auto-min-threshold` 64 MiB; `ebox-reflow-cache-prewarm-gc-auto-max-threshold` 1 GiB; `ebox-reflow-cache-prewarm-gc-auto-initial-threshold` 512 MiB; `ebox-reflow-cache-prewarm-gc-auto-target-layouts` 24; `ebox-reflow-cache-prewarm-gc-cons-percentage` 0.1 |
 | Visual verification | `ebox-visual-check-output-dir` points to the temporary directory used for optional screenshots and reports. |
 
@@ -583,7 +590,7 @@ style-rule functions immediately below are public module-level style APIs.
 | `ebox-flex`, `ebox-flex-item` | Build flex containers and item metadata. |
 | `ebox-grid`, `ebox-grid-fr`, `ebox-grid-item` | Build Grid layouts, fractional tracks, and placement metadata. |
 | `ebox-render`, `ebox-render-to-buffer`, `ebox-display-buffer` | Pure materialization, retained mount, and display wrapper. |
-| `ebox-commit`, `ebox-buffer-update-report`, `ebox-rerender-buffer-with-context` | Atomic root commit, report lookup, and viewport-context rerender. |
+| `ebox-commit`, `ebox-buffer-update-report`, `ebox-rerender-buffer-with-context`, `ebox-viewport-window-width` | Atomic root commit, report lookup, viewport-context rerender, and the shared display-safe width sampler. |
 | `ebox-region-ids`, `ebox-region-resolve`, `ebox-region-update` | Region mapping, logical handle lookup, and direct update. |
 | `ebox-child-range`, `ebox-range-ref-present-p`, `ebox-candidate-begin`, `ebox-candidate-replace`, `ebox-candidate-replace-range-ref`, `ebox-candidate-replace-root`, `ebox-candidate-replace-host-ref`, `ebox-candidate-patch-host-paint` | Persistent material child segments, backend-anchor lookup, subtree replacement, and retained Host paint transactions. |
 | `ebox-host-ref-bounds`, `ebox-host-ref-position` | Live host-reference bounds and first position. |

docs/user/ebox-api-reference.zh.md

@@ -392,6 +392,11 @@ report；若后续 phase 失败，rollback 最多一次接收同一个 report，
 render 外部动态绑定 `ebox-viewport-width`（像素）与 `ebox-viewport-height`
 （行数）。不要原地修改已经发布的 node tree。
 
+可见的 mounted buffer 会自动跟随展示它的 window。Ebox 合并连续 size event，
+并在 `ebox-viewport-resize-delay`（默认 0.05 秒）后只发布最新 sample。
+`ebox-viewport-window-width` 返回 controller 使用的同一个显示安全像素宽度；
+宿主不应再安装第二套 resize hook 或宽度算法。
+
 ## 7. Selector
 
 `ebox-selector-parse` 委托 ECSS 并返回结构化 AST；
@@ -468,6 +473,7 @@ text scale 和固定 `display` space；它也是布局使用的公共测量原
 | Lazy scroll | `ebox-scroll-lazy-prefix-lookahead-lines` 8；`ebox-scroll-lazy-idle-prefetch-lines` 128；`ebox-scroll-lazy-idle-prefetch-slice-lines` 16；`ebox-scroll-lazy-idle-prefetch-delay` 0.15 |
 | Runtime prewarm | `ebox-runtime-idle-prewarm` t；`ebox-runtime-idle-prewarm-delay` 0.1；`ebox-runtime-idle-prewarm-prefix-resume-delay` 2.0；`ebox-runtime-idle-prewarm-slice-size` 32；`ebox-native-buffer-scroll` t（仅 initial/visible-window handoff；严格 root-owner proof） |
 | 预测 reflow | `ebox-runtime-idle-reflow-cache-prewarm` t；`ebox-runtime-idle-reflow-cache-prewarm-delay` 0.15 |
+| Viewport delivery | `ebox-viewport-resize-delay` 0.05；连续 window event 对每个 mounted buffer 只保留一个最新 sample |
 | Reflow GC | `ebox-reflow-cache-prewarm-gc-cons-threshold` `auto`；`ebox-reflow-cache-prewarm-gc-auto-frame-budget` 0.2；`ebox-reflow-cache-prewarm-gc-auto-min-threshold` 64 MiB；`ebox-reflow-cache-prewarm-gc-auto-max-threshold` 1 GiB；`ebox-reflow-cache-prewarm-gc-auto-initial-threshold` 512 MiB；`ebox-reflow-cache-prewarm-gc-auto-target-layouts` 24；`ebox-reflow-cache-prewarm-gc-cons-percentage` 0.1 |
 | Visual verification | `ebox-visual-check-output-dir` 指向可选 screenshot/report 使用的临时目录。 |
 
@@ -531,7 +537,7 @@ style API。
 | `ebox-flex`、`ebox-flex-item` | 构建 Flex 容器与 item metadata。 |
 | `ebox-grid`、`ebox-grid-fr`、`ebox-grid-item` | 构建 Grid、分数轨道和 placement metadata。 |
 | `ebox-render`、`ebox-render-to-buffer`、`ebox-display-buffer` | 纯 materialization、retained mount 与展示包装。 |
-| `ebox-commit`、`ebox-buffer-update-report`、`ebox-rerender-buffer-with-context` | 原子根提交、报告查询和 viewport-context rerender。 |
+| `ebox-commit`、`ebox-buffer-update-report`、`ebox-rerender-buffer-with-context`、`ebox-viewport-window-width` | 原子根提交、报告查询、viewport-context rerender 与统一的显示安全宽度采样。 |
 | `ebox-region-ids`、`ebox-region-resolve`、`ebox-region-update` | Region 映射、logical handle 查询与直接更新。 |
 | `ebox-child-range`、`ebox-range-ref-present-p`、`ebox-candidate-begin`、`ebox-candidate-replace`、`ebox-candidate-replace-range-ref`、`ebox-candidate-replace-root`、`ebox-candidate-replace-host-ref`、`ebox-candidate-patch-host-paint` | 持久 material child segment、backend anchor 查询、子树替换与 retained Host paint transaction。 |
 | `ebox-host-ref-bounds`、`ebox-host-ref-position` | Host-reference 的 live bounds 与首位置。 |

ebox-viewport.el

@@ -0,0 +1,103 @@
+;;; ebox-viewport.el --- Coalesced Emacs viewport delivery -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Emacs owns window events; Ebox owns the mounted viewport.  This module is
+;; the single bridge between them.  Size hooks only sample the latest visible
+;; dimensions.  One deferred callback per buffer publishes the newest sample,
+;; so continuous frame dragging cannot enqueue synchronous layout transactions.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'ebox-surface)
+
+(declare-function ebox--buffer-render-state "ebox-incremental" (buffer))
+(declare-function ebox-rerender-buffer-with-context
+                  "ebox" (buffer viewport-width &optional viewport-height))
+
+(defcustom ebox-viewport-resize-delay 0.05
+  "Seconds after the latest size event before publishing its viewport.
+Continuous size events replace one pending sample for each mounted buffer."
+  :type 'number
+  :group 'ebox)
+
+(defvar ebox--viewport-resize-pending-table (make-hash-table :test #'eq)
+  "Buffer-keyed latest viewport samples awaiting publication.")
+
+(defvar ebox--viewport-resize-generation 0
+  "Monotonic identity for pending viewport samples.")
+
+(defun ebox-viewport-window-width (window)
+  "Return Ebox's display-safe viewport width for live WINDOW."
+  (and (window-live-p window)
+       (ebox-surface--window-content-width window)))
+
+(defun ebox--cancel-buffer-viewport-resize (buffer)
+  "Cancel BUFFER's pending viewport publication."
+  (when-let* ((pending (gethash buffer ebox--viewport-resize-pending-table)))
+    (let ((timer (aref pending 4)))
+      (when (timerp timer) (cancel-timer timer)))
+    (remhash buffer ebox--viewport-resize-pending-table))
+  nil)
+
+(defun ebox--viewport-resize-apply (buffer generation)
+  "Publish BUFFER's pending viewport identified by GENERATION."
+  (when-let* ((pending (gethash buffer ebox--viewport-resize-pending-table)))
+    (when (= generation (aref pending 0))
+      (remhash buffer ebox--viewport-resize-pending-table)
+      (let ((window (aref pending 1))
+            (width (aref pending 2))
+            (height (aref pending 3)))
+        (when (and (buffer-live-p buffer)
+                   (window-live-p window)
+                   (eq (window-buffer window) buffer)
+                   (ebox-surface-buffer-mounted-p buffer))
+          (let ((state (ebox--buffer-render-state buffer)))
+            (unless (and (= width (or (plist-get state :viewport-width) -1))
+                         (= height (or (plist-get state :viewport-height) -1)))
+              (ebox-rerender-buffer-with-context buffer width height))))))))
+
+(defun ebox--schedule-buffer-viewport-resize
+    (buffer window width height)
+  "Replace BUFFER's pending viewport with WINDOW, WIDTH, and HEIGHT."
+  (ebox--cancel-buffer-viewport-resize buffer)
+  (let* ((generation (cl-incf ebox--viewport-resize-generation))
+         (pending (vector generation window width height nil)))
+    (puthash buffer pending ebox--viewport-resize-pending-table)
+    (aset pending 4
+          (run-at-time
+           (max 0 ebox-viewport-resize-delay) nil
+           #'ebox--viewport-resize-apply buffer generation)))
+  buffer)
+
+(defun ebox--window-size-change (frame)
+  "Sample latest viewports for mounted Ebox buffers visible in FRAME."
+  (when (and (frame-live-p frame) (not noninteractive))
+    (let ((seen (make-hash-table :test #'eq)))
+      (dolist (window (window-list frame 'no-minibuf))
+        (when (window-live-p window)
+          (let ((buffer (window-buffer window)))
+            (unless (gethash buffer seen)
+              (puthash buffer t seen)
+              (when (and (buffer-live-p buffer)
+                         (ebox-surface-buffer-mounted-p buffer))
+                (let* ((state (ebox--buffer-render-state buffer))
+                       (width (ebox-viewport-window-width window))
+                       (height (window-body-height window)))
+                  (when (and width
+                             state
+                             (not (and
+                                   (= width
+                                      (or (plist-get state :viewport-width) -1))
+                                   (= height
+                                      (or (plist-get state :viewport-height)
+                                          -1)))))
+                    (ebox--schedule-buffer-viewport-resize
+                     buffer window width height)))))))))))
+
+(when (boundp 'window-size-change-functions)
+  (add-hook 'window-size-change-functions #'ebox--window-size-change))
+
+(provide 'ebox-viewport)
+
+;;; ebox-viewport.el ends here

ebox.el

@@ -26,7 +26,8 @@
   '("ebox-cache.el" "ebox-style.el" "ebox-child-range.el" "ebox-tree.el" "ebox-measure.el"
     "ebox-fragment.el" "ebox-render-context.el" "ebox-layout.el"
     "ebox-flex.el" "ebox-grid.el" "ebox-buffer-backend.el" "ebox-incremental.el"
-    "ebox-native-commit.el" "ebox-surface.el" "ebox-dsl.el" "ebox-selector.el" "ebox.el"
+    "ebox-native-commit.el" "ebox-surface.el" "ebox-viewport.el"
+    "ebox-dsl.el" "ebox-selector.el" "ebox.el"
     "ebox-native-reflow.el")
   "Active Ebox Lisp sources compiled by `ebox-byte-compile'.")
 
@@ -49,6 +50,7 @@
 (require 'ebox-buffer-backend)
 (require 'ebox-incremental)
 (require 'ebox-surface)
+(require 'ebox-viewport)
 (require 'ebox-dsl)
 (require 'ebox-selector)
 
@@ -2742,42 +2744,6 @@ that was rendered off-window cannot miss the native-scroll handoff."
 (when (boundp 'window-state-change-functions)
   (add-hook 'window-state-change-functions #'ebox--window-state-change))
 
-(defvar ebox--window-size-change-in-progress nil
-  "Non-nil while visible Ebox buffers are synchronizing their viewport.")
-
-(defun ebox--window-size-change (frame)
-  "Synchronize visible Ebox buffers after FRAME changes size.
-
-Ebox stores the containing-block viewport in its mounted surface.  A frame
-resize must publish the new window content width before the next render;
-otherwise responsive Flex/Grid trees keep using the width from mount time.
-One mounted surface represents one viewport, so when a buffer is visible in
-multiple windows the first window in FRAME supplies the shared dimensions."
-  (when (and (frame-live-p frame)
-             (not noninteractive)
-             (not ebox--window-size-change-in-progress))
-    (let ((ebox--window-size-change-in-progress t)
-          (seen (make-hash-table :test #'eq)))
-      (dolist (window (window-list frame 'no-minibuf))
-        (when (and (window-live-p window)
-                   (not (gethash (window-buffer window) seen)))
-          (let ((buffer (window-buffer window)))
-            (puthash buffer t seen)
-            (when (and (buffer-live-p buffer)
-                       (ebox--buffer-render-state buffer)
-                       (ebox-surface-buffer-mounted-p buffer))
-              (let* ((state (ebox--buffer-render-state buffer))
-                     (width (ebox-surface--window-content-width window))
-                     (height (window-body-height window)))
-                (unless (and (= width (or (plist-get state :viewport-width)
-                                           -1))
-                             (= height (or (plist-get state :viewport-height)
-                                           -1)))
-                  (ebox-rerender-buffer-with-context buffer width height))))))))))
-
-(when (boundp 'window-size-change-functions)
-  (add-hook 'window-size-change-functions #'ebox--window-size-change))
-
 (defun ebox--runtime-prewarm-record-viewport-node
     (job node width-allowed)
   "Record NODE's direct viewport dependencies in JOB.
@@ -3882,6 +3848,7 @@ With prefix ARG, scroll by that many content lines."
   "Remove all runtime caches owned by BUFFER.
 Defaults to the current buffer."
   (let ((buffer (or buffer (current-buffer))))
+    (ebox--cancel-buffer-viewport-resize buffer)
     (ebox--cancel-buffer-runtime-prewarm buffer)
     (when-let ((root (ebox--buffer-root-node buffer)))
       (ebox--clear-region-runtime-caches
@@ -4716,6 +4683,7 @@ through dirty-set and patch-set execution before falling back to root rerender."
     ebox-stack
     ebox-string-pixel-width
     ebox-update-selector
+    ebox-viewport-window-width
     ebox-wheel-scroll-down
     ebox-wheel-scroll-up)
   "Stable core Ebox entry points available to applications and tooling.

tests/ebox-child-range-tests.el

@@ -4,6 +4,11 @@
 (require 'ebox-child-range)
 (require 'ebox)
 
+;; This suite locks child-range and Elisp projection semantics.  Native frame
+;; execution is verified separately and must not replace the named fallback
+;; strategies merely because a developer has built the optional module.
+(setq ebox-native-reflow-module-path nil)
+
 (defconst ebox-child-range-test--root
   (expand-file-name ".." (file-name-directory (or load-file-name buffer-file-name)))
   "Ebox repository root for source audits.")

tests/ebox-commit-tests.el

@@ -5,6 +5,12 @@
 (require 'ebox)
 (require 'ebox-native-commit)
 
+;; These tests lock the named Elisp projection proofs.  Native commit has its
+;; own focused contract tests below; disable runtime module discovery here so
+;; a locally built optional module cannot silently replace paint/span/mixed
+;; plans with `native-frame' and make this suite environment-dependent.
+(setq ebox-native-reflow-module-path nil)
+
 (defun ebox-commit-test--buffer-string (buffer)
   "Return BUFFER's complete propertized contents."
   (with-current-buffer buffer

tests/ebox-core-render-tests.el

@@ -10,6 +10,11 @@
 
 (load-file (expand-file-name "../ebox.el" (file-name-directory load-file-name)))
 
+;; Core tests assert named Elisp render/patch strategies.  Keep optional local
+;; native artifacts from replacing those strategies; native execution has
+;; separate module and integration gates.
+(setq ebox-native-reflow-module-path nil)
+
 (defvar ebox--scroll-window-initial-lookahead-lines-override nil)
 
 (defun ebox-test--reset-runtime-state ()

tests/ebox-package-tests.el

@@ -51,7 +51,8 @@
   (dolist (feature '(ebox-cache ebox-style ebox-tree ebox-measure
                                 ebox-fragment ebox-layout ebox-flex ebox-grid
                                 ebox-buffer-backend ebox-incremental
-                                ebox-surface ebox-dsl ebox-selector))
+                                ebox-surface ebox-viewport ebox-dsl
+                                ebox-selector))
     (should (featurep feature))))
 
 (ert-deftest ebox-facade-exposes-native-workflow-without-loading-it ()
@@ -70,8 +71,8 @@
             "ebox-tree.el" "ebox-measure.el"
             "ebox-fragment.el" "ebox-render-context.el" "ebox-layout.el"
             "ebox-flex.el" "ebox-grid.el" "ebox-buffer-backend.el" "ebox-incremental.el"
-            "ebox-native-commit.el" "ebox-surface.el" "ebox-dsl.el"
+            "ebox-native-commit.el" "ebox-surface.el" "ebox-viewport.el"
-            "ebox-selector.el" "ebox.el"
+            "ebox-dsl.el" "ebox-selector.el" "ebox.el"
             "ebox-native-reflow.el"))))
 
 (ert-deftest ebox-surface-depends-only-on-public-tp-api ()

tests/ebox-surface-tests.el

@@ -171,11 +171,15 @@
       (when (get-buffer " *other-window*")
         (kill-buffer " *other-window*")))))
 
-(ert-deftest ebox-window-size-change-publishes-visible-viewport ()
+(ert-deftest ebox-window-size-change-coalesces-to-latest-visible-viewport ()
-  "A live frame resize updates the mounted surface's containing block."
+  "Continuous frame changes publish only the latest sampled viewport."
   (let* ((buffer (generate-new-buffer " *ebox-window-size-change*"))
          (window (selected-window))
          (old-buffer (window-buffer window))
+         (sampled-height (window-body-height window))
+         (sampled-widths (number-sequence 240 430 10))
+         scheduled
+         cancelled
          calls)
     (unwind-protect
         (progn
@@ -186,18 +190,58 @@
                     ((symbol-function 'ebox-surface-buffer-mounted-p)
                      (lambda (_buffer) t))
                     ((symbol-function 'ebox-surface--window-content-width)
-                     (lambda (_window) 240))
+                     (lambda (_window) (pop sampled-widths)))
-                    ((symbol-function 'window-body-height)
-                     (lambda (_window &optional _pixelwise) 20))
                     ((symbol-function 'ebox-rerender-buffer-with-context)
                      (lambda (target width height)
-                       (setq calls (list target width height))))
+                       (push (list target width height) calls)))
+                    ((symbol-function 'run-at-time)
+                     (lambda (delay _repeat function &rest arguments)
+                       (let ((timer (intern (format "ebox-resize-timer-%d"
+                                                    (1+ (length scheduled))))))
+                         (push (list timer delay function arguments) scheduled)
+                         timer)))
+                    ((symbol-function 'timerp)
+                     (lambda (value)
+                       (string-prefix-p "ebox-resize-timer-"
+                                        (symbol-name value))))
+                    ((symbol-function 'cancel-timer)
+                     (lambda (timer) (push timer cancelled)))
                     (noninteractive nil))
-            (ebox--window-size-change (selected-frame))
+            (dotimes (_index 20)
-            (should (equal calls (list buffer 240 20)))))
+              (ebox--window-size-change (selected-frame)))
+            (should-not calls)
+            (should (= (length scheduled) 20))
+            (should (= (length cancelled) 19))
+            (pcase-let ((`(,_timer ,delay ,function ,arguments)
+                         (car scheduled)))
+              (should (= delay ebox-viewport-resize-delay))
+              (apply function arguments))
+            (should (equal calls
+                           (list (list buffer 430 sampled-height))))))
       (set-window-buffer window old-buffer)
+      (when (boundp 'ebox--viewport-resize-pending-table)
+        (clrhash ebox--viewport-resize-pending-table))
       (kill-buffer buffer))))
 
+(ert-deftest ebox-buffer-cleanup-cancels-pending-viewport-resize ()
+  "A dead mounted buffer cannot retain a viewport timer or pending sample."
+  (let ((buffer (generate-new-buffer " *ebox-viewport-cleanup*"))
+        (timer 'ebox-test-viewport-cleanup-timer)
+        cancelled)
+    (unwind-protect
+        (progn
+          (puthash buffer (vector 1 (selected-window) 400 20 timer)
+                   ebox--viewport-resize-pending-table)
+          (cl-letf (((symbol-function 'timerp)
+                     (lambda (value) (eq value timer)))
+                    ((symbol-function 'cancel-timer)
+                     (lambda (value) (setq cancelled value))))
+            (with-current-buffer buffer (ebox--cleanup-current-buffer)))
+          (should (eq cancelled timer))
+          (should-not (gethash buffer ebox--viewport-resize-pending-table)))
+      (remhash buffer ebox--viewport-resize-pending-table)
+      (when (buffer-live-p buffer) (kill-buffer buffer)))))
+
 (defun ebox-surface-test--hash-fingerprint (table)
   "Return a stable content fingerprint for hash TABLE.
 The fingerprint checks entries rather than only table identity, so a failed
@@ -732,10 +776,13 @@ candidate cannot hide mutations by restoring the old hash-table pointer."
 
 (ert-deftest ebox-surface-plan-stays-free-of-runtime-state ()
   "The surface plan should not contain markers or runtime handles."
+  (require 'ebox-native-commit)
   (let ((original (symbol-function 'tp-surface-result-create))
         (original-owned (symbol-function 'tp-surface-result-create-owned))
         captured client-state)
-    (cl-letf (((symbol-function 'tp-surface-result-create)
+    (cl-letf (((symbol-function 'ebox-native-commit-render)
+               (lambda (&rest _) nil))
+              ((symbol-function 'tp-surface-result-create)
                (lambda (plan &optional state)
                  (setq captured plan
                        client-state state)
@@ -753,7 +800,8 @@ candidate cannot hide mutations by restoring the old hash-table pointer."
     (let* ((fragments-plan (car (tp-surface-plan-children captured)))
            (text-plan (car (tp-surface-plan-children fragments-plan)))
            (plan-text (tp-surface-plan-text text-plan))
-           (state-fragments (plist-get client-state :surface-fragments))
+           (state-fragments
+            (ebox-surface--materialized-fragment-ledger client-state))
            (owner-position
             (cl-loop for position from 0 below (length plan-text)
                      when (get-text-property position
@@ -1323,7 +1371,9 @@ candidate cannot hide mutations by restoring the old hash-table pointer."
                   (plist-put node :key 'growing-source)
                   node))
           (let ((original-render (symbol-function 'ebox-render)))
-            (cl-letf (((symbol-function 'ebox-render)
+            (cl-letf (((symbol-function 'ebox-native-commit-render)
+                       (lambda (&rest _) nil))
+                      ((symbol-function 'ebox-render)
                        (lambda (node)
                          (cond
                           ((equal (plist-get node :key) 'stable-source)