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Fix browser freeze after pane split #1852

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Merged
austinywang merged 1 commit into from
Mar 23, 2026
Merged

Fix browser freeze after pane split #1852

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16 changes: 16 additions & 0 deletions Sources/Panels/BrowserPanelView.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -6064,6 +6064,10 @@ struct WebViewRepresentable: NSViewRepresentable {
visibleInUI: coordinator.desiredPortalVisibleInUI,
zPriority: coordinator.desiredPortalZPriority
)
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind.didMoveToWindow"
)
Comment on lines +6067 to +6070

@greptile-apps greptile-apps Bot Mar 20, 2026

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P2 onDidMoveToWindow refresh fires unconditionally on every window-entry event

Unlike the onGeometryChanged handler (which guards with coordinator.lastPortalHostId != hostId || !isWebView(boundTo:) before calling bind + refresh), this path calls bind() + refresh() on every invocation that passes the generation/ownership/window guards — even when the host hasn't changed.

refreshHostedWebViewPresentation schedules three layout + browserPortalReattachRenderingState passes (immediate, async, and asyncAfter +30 ms), guarded only by containerView.isHidden. If the container is visible at the moment onDidMoveToWindow fires (e.g., after SwiftUI recreates the host view during a workspace transition while the pane is in view), all three passes run unnecessarily.

Consider adding an early-exit guard consistent with onGeometryChanged:

Suggested change
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind.didMoveToWindow"
)
Self.installPortalAnchorView(portalAnchorView, in: host)
let hostId = ObjectIdentifier(host)
let needsRebind = coordinator.lastPortalHostId != hostId ||
!BrowserWindowPortalRegistry.isWebView(webView, boundTo: portalAnchorView)
BrowserWindowPortalRegistry.bind(
webView: webView,
to: portalAnchorView,
visibleInUI: coordinator.desiredPortalVisibleInUI,
zPriority: coordinator.desiredPortalZPriority
)
if needsRebind {
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind.didMoveToWindow"
)
}

This mirrors the guard already present in onGeometryChanged and avoids the three-pass refresh cycle on ordinary re-presentations where the host–anchor binding is already correct.

BrowserWindowPortalRegistry.updatePaneTopChromeHeight(
for: webView,
height: coordinator.desiredPortalVisibleInUI ? paneTopChromeHeight : 0
Expand Down Expand Up @@ -6095,6 +6099,10 @@ struct WebViewRepresentable: NSViewRepresentable {
visibleInUI: coordinator.desiredPortalVisibleInUI,
zPriority: coordinator.desiredPortalZPriority
)
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind.geometryChanged"
)
Comment on lines +6102 to +6105

@greptile-apps greptile-apps Bot Mar 20, 2026

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P2 Missing explanatory comment in onGeometryChanged refresh path

The shouldBindNow path has a detailed comment explaining why refresh() is required (cycling _exitInWindow/_enterInWindow after a pane split reparents the WKWebView). The same rationale applies here — a new hostId means the web view was reparented — but there's no comment, which can make this call look like unnecessary churn to a future reader.

Suggested change
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind.geometryChanged"
)
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind.geometryChanged"
)
// Force a rendering-state reattach after portal host replacement
// (e.g. after a pane split). Without this, WKWebView can freeze
// because _exitInWindow/_enterInWindow are never cycled when the
// web view is reparented to a new container during bind.

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!

BrowserWindowPortalRegistry.updatePaneTopChromeHeight(
for: webView,
height: coordinator.desiredPortalVisibleInUI ? paneTopChromeHeight : 0
Expand Down Expand Up @@ -6132,6 +6140,14 @@ struct WebViewRepresentable: NSViewRepresentable {
visibleInUI: coordinator.desiredPortalVisibleInUI,
zPriority: coordinator.desiredPortalZPriority
)
// Force a rendering-state reattach after portal host replacement
// (e.g. after a pane split). Without this, WKWebView can freeze
// because _exitInWindow/_enterInWindow are never cycled when the
// web view is reparented to a new container during bind.
BrowserWindowPortalRegistry.refresh(
webView: webView,
reason: "portalHostBind"
)
coordinator.lastPortalHostId = hostId
coordinator.lastSynchronizedHostGeometryRevision = geometryRevision
}
Expand Down