✨ Sync 2026-08-20 17:28:50

luci-theme-footstrap/htdocs/luci-static/resources/fs-fit.js

@@ -338,6 +338,12 @@ let _restAt = null, _restPage = null;
 function pageStamp() {
 	return (document.body && document.body.getAttribute('data-page')) || '';
 }
+/* -> the memo is void: whoever calls this owns the offset now (see the export below) */
+function forgetRest() {
+	_rest = null;
+	_restAt = null;
+	_restPage = null;
+}
 function rememberRest() {
 	if (ENGINE_ANCHORS || scrolling()) return;
 	const ref = anchorRef();
@@ -588,6 +594,17 @@ return baseclass.extend({
 	scrolling,
 	deferMeasurement,
 
+	/* "THE OFFSET IS MINE NOW, FORGET WHAT YOU REMEMBERED." Called by fs-router where it resets both
+	 * scrollers for an incoming page, and it is not a courtesy — without it the correction below
+	 * fights that reset. The router resets synchronously and stamps `body[data-page]` an await later,
+	 * so between the two there is a window, as long as the incoming view takes to arrive, in which a
+	 * poll tick from the OUTGOING page still fires: the offset is 0, the remembered one is where the
+	 * reader was, nobody is scrolling and the stamp still names the page they came from — every term
+	 * of "the engine clamped this" is true, and the reader would be dragged back down a page they
+	 * have left, with the new page committing mid-scroll. Reported in review on the upstream
+	 * proposal. The stamp cannot close it alone, because it is written afterwards. */
+	forgetRest,
+
 	/* Raise the stylesheet's "an unanswered table takes no room" rule. Called by the module that
 	 * answers — see armGate above; nothing else may call it. */
 	armGate,

luci-theme-footstrap/htdocs/luci-static/resources/fs-overview.js

@@ -25,7 +25,7 @@
  *
  * WHAT THAT COST, and why the code below looks the way it does: the old location bought two timing
  * guarantees for free, because LuCI evaluated the file INSIDE index.load(). Both had to be paid for
- * explicitly — see ensureOverviewHelpers() and patchOverview() at the bottom. */
+ * explicitly — see patchOverview() below and ensureOverviewHelpers() in menu-footstrap-common.js. */
 /* section title -> grid role. _() with NO msgctxt on purpose: these must resolve to exactly what
  * luci-mod-status resolves to, or the titles stop matching. Built once — it used to cost an
  * allocation plus three _() lookups per poll tick. */
@@ -191,44 +191,10 @@ function fillSection(inc, container, res) {
 		container.parentNode.style.display = '';
 		container.parentNode.classList.add('fade-in');
 		if (!inc.hide)
-			swapContent(container, content);
+			dom.content(container, content);
 	}
 }
 
-/* WHAT `dom.content()` DOES TO A READER TWO SCREENS DOWN, and the reason a section is filled through
- * here rather than through it directly.
- *
- * `dom.content()` removes every child and then appends the new ones. Between those two halves the
- * section has NO height, and a document that just lost several hundred pixels is a document the
- * engine clamps the scroll offset into: the offset drops to whatever length is left, the section
- * fills again, and nothing puts the offset back. The reader is now somewhere else, once a second,
- * for as long as the Overview is open. Reported from Safari on macOS and iOS with the offset moving
- * 200-887px per tick, and reproduced in WebKit with the engine's own scroll anchoring off: a 30-row
- * section swapped for a 35-row one two screens above the reader moved the page 255px under them —
- * 0px with the height held across the swap.
- *
- * fs-fit's anchoring covers the same fault from the other side (it now recognises a clamped offset
- * and puts the reader back), and it has to: every OTHER page's poll calls `dom.content()` too and no
- * theme code is in that path. This is the half that can be prevented rather than corrected, and
- * prevention is worth the line — a correction is a scroll the reader did not ask for, and on iOS it
- * lands in the middle of whatever momentum the page still has.
- *
- * The cost is one `offsetHeight` per filled section per tick — a forced layout, which this theme
- * spends carefully (fs-fit.js). It is paid because the alternative is not "no layout" but "a layout
- * whose result is the page jumping": the swap dirties this container anyway.
- *
- * The pin is released in the same call, so nothing is left to a later frame that could take the
- * minimum with it if the next tick throws — and a section that legitimately got shorter is shorter
- * again by the time this returns. */
-function swapContent(container, content) {
-	const hold = container.offsetHeight;
-	const prev = container.style.minHeight;
-	if (hold > 0)
-		container.style.minHeight = hold + 'px';
-	try { dom.content(container, content); }
-	finally { if (hold > 0) container.style.minHeight = prev; }
-}
-
 let _inflight = null;
 /* WHICH containers the in-flight run is filling. The guard below is module-level because the
  * duplicate load it kills is module-level, but the frames are per RENDER — so joining a run blindly

luci-theme-footstrap/htdocs/luci-static/resources/fs-router.js

@@ -5,6 +5,7 @@
 'require fs-menutree as tree';
 'require fs-chrome as chrome';
 'require fs-sheets as sheets';
+'require fs-fit as fit';
 
 /* ---- SPA client router ----
  *
@@ -1091,6 +1092,12 @@ function navigate(pathname, push, kbd) {
 	 * swap and is undone by it (see restoreScroll above), so it neither helps nor hurts, and 'manual' would only take away
 	 * the case that does work — a genuine full load. */
 	if (push) {
+		/* BEFORE the two writes, and the order is the point: fs-fit keeps the offset the reader was
+		 * last still at, so it can tell an engine's clamp from a reader who moved. This reset is
+		 * neither, and it lands a whole require ahead of the `data-page` stamp fs-fit would otherwise
+		 * notice it by — so a poll tick from the page being left would read the reset as a clamp and
+		 * put the reader back on it. Told rather than inferred. */
+		fit.forgetRest();
 		window.scrollTo(0, 0);
 		const sc = document.getElementById('maincontent');
 		if (sc) sc.scrollTo(0, 0);