Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 98a1df0a260dab874c97274992b92f2ef667d053
https://github.com/WebKit/WebKit/commit/98a1df0a260dab874c97274992b92f2ef667d053
Author: Sihui Liu <[email protected]>
Date: 2026-07-17 (Fri, 17 Jul 2026)
Changed paths:
M Source/WebKit/UIProcess/WebProcessPool.cpp
Log Message:
-----------
[Site Isolation] Fix TestWebKitAPI.ProcessSwap.NavigateToDataURLThenBack
https://bugs.webkit.org/show_bug.cgi?id=319440
rdar://182254652
Reviewed by Basuke Suzuki.
Commit 314948@main fixed BFCache restore for back-navigation through a data:
URL under Site
Isolation by forcing a process swap on main-frame data: URL navigations.
However, this broke the
existing behavior that data: URL navigations should stay in the same process,
which is consistent
with other browsers.
The process swap is unnecessary because the in-process BFCache
(WebCore::BackForwardCache) handles
this case correctly on its own: when navigating from a regular page to a data:
URL without a process
swap, the source page is suspended into the in-process BFCache and is correctly
restored on back
navigation.
Revert the data: URL carve-out from processForNavigationInternal, restoring
data: URLs to
same-origin treatment (no process swap) under Site Isolation.
However, this exposed a separate gap: when navigating back to a page that was
cached only via the
in-process BFCache (no SuspendedPageProxy, because no process swap occurred),
processForNavigation
under Site Isolation had no way to find the correct process. It checked
targetItem->suspendedPage()
but not targetItem->backForwardCacheEntry(). Since the WebContent process
already notifies the
UIProcess via didCacheBackForwardItem (which calls
WebBackForwardCache::addEntry with the process
identifier), a valid BackForwardCacheEntry exists on the item — it just wasn't
being consulted.
Add a fallback in processForNavigation: after the suspendedPage check, also
check
backForwardCacheEntry() and reuse its process when available. This ensures back
navigation to pages
cached via in-process BFCache correctly reuses the original process instead of
spawning a new one.
The !site.isEmpty() gate fix from 314948@main (which allows SuspendedPageProxy
lookup for
back-navigations to file:// and other empty-site URLs) is intentionally kept as
it is an independent
improvement.
* Source/WebKit/UIProcess/WebProcessPool.cpp:
(WebKit::WebProcessPool::processForNavigation):
(WebKit::WebProcessPool::processForNavigationInternal):
Canonical link: https://commits.webkit.org/317435@main
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