diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 629efb5..1eb4b3f 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,26 @@
+2019-10-12  Chris Dumez  <cdumez@apple.com>
+
+        Back/Forward cache does not work after doing a favorite navigation
+        https://bugs.webkit.org/show_bug.cgi?id=202762
+        <rdar://problem/56126911>
+
+        Reviewed by Antti Koivisto.
+
+        When a subframe goes into the page cache, make sure we null out the opener
+        link of any windows that were opened by this frame. This matches what would
+        happened if this frame were closed.
+
+        Covered by the following API tests:
+        ProcessSwap.PageCacheAfterProcessSwapByClient
+        ProcessSwap.OpenerLinkAfterAPIControlledProcessSwappingOfOpener
+
+        * history/CachedFrame.cpp:
+        (WebCore::CachedFrame::CachedFrame):
+        * loader/FrameLoader.cpp:
+        (WebCore::FrameLoader::~FrameLoader):
+        (WebCore::FrameLoader::detachFromAllOpenedFrames):
+        * loader/FrameLoader.h:
+
 2019-10-12  Chris Fleizach  <cfleizach@apple.com>
 
         AX: Make AXIsolatedTree compile again
diff --git a/Source/WebCore/history/CachedFrame.cpp b/Source/WebCore/history/CachedFrame.cpp
index df78c03..59a26b9 100644
--- a/Source/WebCore/history/CachedFrame.cpp
+++ b/Source/WebCore/history/CachedFrame.cpp
@@ -179,6 +179,10 @@
     // 'DidFirstVisuallyNonEmptyLayout' callback gets called against when restoring from PageCache.
     m_view->resetLayoutMilestones();
 
+    // The main frame is reused for the navigation and the opener link to its should thus persist.
+    if (!frame.isMainFrame())
+        frame.loader().detachFromAllOpenedFrames();
+
     frame.loader().client().savePlatformDataToCachedFrame(this);
 
     // documentWillSuspendForPageCache() can set up a layout timer on the FrameView, so clear timers after that.
diff --git a/Source/WebCore/loader/FrameLoader.cpp b/Source/WebCore/loader/FrameLoader.cpp
index 61a0aeb..fd84cb1 100644
--- a/Source/WebCore/loader/FrameLoader.cpp
+++ b/Source/WebCore/loader/FrameLoader.cpp
@@ -297,9 +297,7 @@
 FrameLoader::~FrameLoader()
 {
     setOpener(nullptr);
-
-    for (auto& frame : m_openedFrames)
-        frame->loader().m_opener = nullptr;
+    detachFromAllOpenedFrames();
 
     m_client.frameLoaderDestroyed();
 
@@ -307,6 +305,13 @@
         m_networkingContext->invalidate();
 }
 
+void FrameLoader::detachFromAllOpenedFrames()
+{
+    for (auto& frame : m_openedFrames)
+        frame->loader().m_opener = nullptr;
+    m_openedFrames.clear();
+}
+
 void FrameLoader::init()
 {
     // This somewhat odd set of steps gives the frame an initial empty document.
diff --git a/Source/WebCore/loader/FrameLoader.h b/Source/WebCore/loader/FrameLoader.h
index 671bad4..a3716d9 100644
--- a/Source/WebCore/loader/FrameLoader.h
+++ b/Source/WebCore/loader/FrameLoader.h
@@ -253,6 +253,7 @@
 
     WEBCORE_EXPORT Frame* opener();
     WEBCORE_EXPORT void setOpener(Frame*);
+    WEBCORE_EXPORT void detachFromAllOpenedFrames();
     bool hasOpenedFrames() const { return !m_openedFrames.isEmpty(); }
 
     void resetMultipleFormSubmissionProtection();
diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
index 6a3688c..3c5546b 100644
--- a/Source/WebKit/ChangeLog
+++ b/Source/WebKit/ChangeLog
@@ -1,5 +1,27 @@
 2019-10-12  Chris Dumez  <cdumez@apple.com>
 
+        Back/Forward cache does not work after doing a favorite navigation
+        https://bugs.webkit.org/show_bug.cgi?id=202762
+        <rdar://problem/56126911>
+
+        Reviewed by Antti Koivisto.
+
+        When a process-swap was forced by the client, we would always close the page in the previous
+        process after navigating. This would prevent leveraging the back/forward cache when navigating
+        back after such a process-swap. The reason we were doing this is that other pages may have
+        opener link to this page and closing the page was an easy way to break this opener link.
+
+        To address the issue, we no longer close the previous page when a process-swap is forced by the
+        client. Instead, we make sure to disconnect the frames' openees from their opener then the opener
+        enters the page cache.
+
+        * UIProcess/WebPageProxy.cpp:
+        (WebKit::WebPageProxy::suspendCurrentPageIfPossible):
+        * WebProcess/WebPage/WebPage.cpp:
+        (WebKit::WebPage::suspendForProcessSwap):
+
+2019-10-12  Chris Dumez  <cdumez@apple.com>
+
         Clearing Website data for a given session should not shut down cached processes for other sessions
         https://bugs.webkit.org/show_bug.cgi?id=202865
         <rdar://problem/56202912>
diff --git a/Source/WebKit/UIProcess/WebPageProxy.cpp b/Source/WebKit/UIProcess/WebPageProxy.cpp
index 01876c6..82e2c4f 100644
--- a/Source/WebKit/UIProcess/WebPageProxy.cpp
+++ b/Source/WebKit/UIProcess/WebPageProxy.cpp
@@ -796,11 +796,6 @@
 
     LOG(ProcessSwapping, "WebPageProxy %" PRIu64 " created suspended page %s for process pid %i, back/forward item %s" PRIu64, identifier().toUInt64(), suspendedPage->loggingString(), m_process->processIdentifier(), fromItem ? fromItem->itemID().logString() : 0);
 
-    // If the client forced a swap then it may not be web-compatible to keep the previous page because other windows may have an opener link to it. We thus close it as soon as we
-    // can do so without flashing.
-    if (processSwapRequestedByClient == ProcessSwapRequestedByClient::Yes)
-        suspendedPage->closeWithoutFlashing();
-
     m_lastSuspendedPage = makeWeakPtr(*suspendedPage);
 
     if (fromItem && shouldUseBackForwardCache())
diff --git a/Source/WebKit/WebProcess/WebPage/WebPage.cpp b/Source/WebKit/WebProcess/WebPage/WebPage.cpp
index b790c3c..6ca57ce 100644
--- a/Source/WebKit/WebProcess/WebPage/WebPage.cpp
+++ b/Source/WebKit/WebProcess/WebPage/WebPage.cpp
@@ -1491,6 +1491,12 @@
         return;
     }
 
+    // Page cache does not break the opener link for the main frame (only does so for the subframes) because the
+    // main frame is normally re-used for the navigation. However, in the case of process-swapping, the main frame
+    // is now hosted in another process and the one in this process is in the cache.
+    if (m_mainFrame && m_mainFrame->coreFrame())
+        m_mainFrame->coreFrame()->loader().detachFromAllOpenedFrames();
+
     send(Messages::WebPageProxy::DidSuspendAfterProcessSwap());
 }
 
diff --git a/Tools/ChangeLog b/Tools/ChangeLog
index 8f8d3b8..89924d5 100644
--- a/Tools/ChangeLog
+++ b/Tools/ChangeLog
@@ -1,3 +1,15 @@
+2019-10-12  Chris Dumez  <cdumez@apple.com>
+
+        Back/Forward cache does not work after doing a favorite navigation
+        https://bugs.webkit.org/show_bug.cgi?id=202762
+        <rdar://problem/56126911>
+
+        Reviewed by Antti Koivisto.
+
+        Add API test coverage.
+
+        * TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm:
+
 2019-10-12  Ryosuke Niwa  <rniwa@webkit.org>
 
         requestIdleCallback cannot be enabled in DumpRenderTree on Windows
diff --git a/Tools/TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm b/Tools/TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm
index 5d68b8d..ee40378 100644
--- a/Tools/TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm
+++ b/Tools/TestWebKitAPI/Tests/WebKitCocoa/ProcessSwapOnNavigation.mm
@@ -3224,6 +3224,82 @@
     EXPECT_EQ(2u, seenPIDs.size());
 }
 
+TEST(ProcessSwap, PageCacheAfterProcessSwapByClient)
+{
+    auto processPoolConfiguration = psonProcessPoolConfiguration();
+    auto processPool = adoptNS([[WKProcessPool alloc] _initWithConfiguration:processPoolConfiguration.get()]);
+
+    auto webViewConfiguration = adoptNS([[WKWebViewConfiguration alloc] init]);
+    [webViewConfiguration setProcessPool:processPool.get()];
+    auto handler = adoptNS([[PSONScheme alloc] init]);
+    [handler addMappingFromURLString:@"pson://www.webkit.org/main1.html" toData:pageCache1Bytes];
+    [handler addMappingFromURLString:@"pson://www.webkit.org/main2.html" toData:pageCache1Bytes];
+    [webViewConfiguration setURLSchemeHandler:handler.get() forURLScheme:@"PSON"];
+
+    auto messageHandler = adoptNS([[PSONMessageHandler alloc] init]);
+    [[webViewConfiguration userContentController] addScriptMessageHandler:messageHandler.get() name:@"pson"];
+
+    auto webView = adoptNS([[WKWebView alloc] initWithFrame:NSMakeRect(0, 0, 800, 600) configuration:webViewConfiguration.get()]);
+    auto delegate = adoptNS([[PSONNavigationDelegate alloc] init]);
+    [webView setNavigationDelegate:delegate.get()];
+
+    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"pson://www.webkit.org/main1.html"]];
+
+    [webView loadRequest:request];
+    TestWebKitAPI::Util::run(&done);
+    done = false;
+
+    auto pidAfterLoad1 = [webView _webProcessIdentifier];
+
+    EXPECT_EQ(1u, [processPool _webProcessCountIgnoringPrewarmedAndCached]);
+
+    // We force a proces-swap via client API.
+    delegate->decidePolicyForNavigationAction = ^(WKNavigationAction *, void (^decisionHandler)(WKNavigationActionPolicy)) {
+        decisionHandler(_WKNavigationActionPolicyAllowInNewProcess);
+    };
+
+    request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"pson://www.webkit.org/main2.html"]];
+
+    [webView loadRequest:request];
+    TestWebKitAPI::Util::run(&done);
+    done = false;
+
+    auto pidAfterLoad2 = [webView _webProcessIdentifier];
+
+    EXPECT_EQ(2u, [processPool _webProcessCountIgnoringPrewarmedAndCached]);
+    EXPECT_NE(pidAfterLoad1, pidAfterLoad2);
+
+    delegate->decidePolicyForNavigationAction = nil;
+
+    [webView goBack];
+    TestWebKitAPI::Util::run(&receivedMessage);
+    receivedMessage = false;
+    TestWebKitAPI::Util::run(&done);
+    done = false;
+
+    auto pidAfterLoad3 = [webView _webProcessIdentifier];
+
+    EXPECT_EQ(2u, [processPool _webProcessCountIgnoringPrewarmedAndCached]);
+    EXPECT_EQ(pidAfterLoad1, pidAfterLoad3);
+    EXPECT_EQ(1u, [receivedMessages count]);
+    EXPECT_TRUE([receivedMessages.get()[0] isEqualToString:@"Was persisted" ]);
+    EXPECT_EQ(2u, seenPIDs.size());
+
+    [webView goForward];
+    TestWebKitAPI::Util::run(&receivedMessage);
+    receivedMessage = false;
+    TestWebKitAPI::Util::run(&done);
+    done = false;
+
+    auto pidAfterLoad4 = [webView _webProcessIdentifier];
+
+    EXPECT_EQ(2u, [processPool _webProcessCountIgnoringPrewarmedAndCached]);
+    EXPECT_EQ(pidAfterLoad2, pidAfterLoad4);
+    EXPECT_EQ(2u, [receivedMessages count]);
+    EXPECT_TRUE([receivedMessages.get()[1] isEqualToString:@"Was persisted" ]);
+    EXPECT_EQ(2u, seenPIDs.size());
+}
+
 TEST(ProcessSwap, PageCacheWhenNavigatingFromJS)
 {
     auto processPoolConfiguration = psonProcessPoolConfiguration();