Bug 1665710: don't update session history for about:blank transient pages r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D90589

docshell/base/CanonicalBrowsingContext.cpp

@@ -39,6 +39,7 @@
 using namespace mozilla::ipc;
 
 extern mozilla::LazyLogModule gAutoplayPermissionLog;
+extern mozilla::LazyLogModule gSHLog;
 
 #define AUTOPLAY_LOG(msg, ...) \
   MOZ_LOG(gAutoplayPermissionLog, LogLevel::Debug, (msg, ##__VA_ARGS__))
@@ -354,6 +355,9 @@ CanonicalBrowsingContext::CreateLoadingSessionHistoryEntryForLoad(
       aLoadState->GetLoadingSessionHistoryInfo();
   if (existingLoadingInfo) {
     entry = SessionHistoryEntry::GetByLoadId(existingLoadingInfo->mLoadId);
+    MOZ_LOG(gSHLog, LogLevel::Verbose,
+            ("SHEntry::GetByLoadId(%" PRIu64 ") -> %p",
+             existingLoadingInfo->mLoadId, entry.get()));
   } else {
     entry = new SessionHistoryEntry(aLoadState, aChannel);
     if (IsTop()) {

docshell/base/nsDocShell.cpp

@@ -280,7 +280,7 @@ static mozilla::LazyLogModule gDocShellAndDOMWindowLeakLogging(
 #endif
 static mozilla::LazyLogModule gDocShellLeakLog("nsDocShellLeak");
 extern mozilla::LazyLogModule gPageCacheLog;
-static mozilla::LazyLogModule gSHLog("SessionHistory");
+mozilla::LazyLogModule gSHLog("SessionHistory");
 
 const char kBrandBundleURL[] = "chrome://branding/locale/brand.properties";
 const char kAppstringsBundleURL[] =
@@ -5689,7 +5689,8 @@ nsresult nsDocShell::RefreshURIFromQueue() {
 }
 
 nsresult nsDocShell::Embed(nsIContentViewer* aContentViewer,
-                           WindowGlobalChild* aWindowActor) {
+                           WindowGlobalChild* aWindowActor,
+                           bool aIsTransientAboutBlank) {
   // Save the LayoutHistoryState of the previous document, before
   // setting up new document
   PersistLayoutHistoryState();
@@ -5714,7 +5715,8 @@ nsresult nsDocShell::Embed(nsIContentViewer* aContentViewer,
     SetHistoryEntryAndUpdateBC(Nothing(), Some<nsISHEntry*>(mLSHE));
   }
 
-  if (StaticPrefs::fission_sessionHistoryInParent()) {
+  if (!aIsTransientAboutBlank &&
+      StaticPrefs::fission_sessionHistoryInParent()) {
     MOZ_LOG(gSHLog, LogLevel::Debug, ("document %p Embed", this));
     MoveLoadingToActiveEntry(mLoadType != LOAD_ERROR_PAGE);
   }
@@ -6764,7 +6766,7 @@ nsresult nsDocShell::CreateAboutBlankContentViewer(
       // hook 'em up
       if (viewer) {
         viewer->SetContainer(this);
-        rv = Embed(viewer, aActor);
+        rv = Embed(viewer, aActor, true);
         NS_ENSURE_SUCCESS(rv, rv);
 
         SetCurrentURI(blankDoc->GetDocumentURI(), nullptr, true, 0);

docshell/base/nsDocShell.h

@@ -1009,7 +1009,8 @@ class nsDocShell final : public nsDocLoader,
   nsresult EnsureCommandHandler();
   nsresult RefreshURIFromQueue();
   nsresult Embed(nsIContentViewer* aContentViewer,
-                 mozilla::dom::WindowGlobalChild* aWindowActor = nullptr);
+                 mozilla::dom::WindowGlobalChild* aWindowActor = nullptr,
+                 bool aIsTransientAboutBlank = false);
   nsPresContext* GetEldestPresContext();
   nsresult CheckLoadingPermissions();
   nsresult LoadHistoryEntry(nsISHEntry* aEntry, uint32_t aLoadType);

docshell/shistory/SessionHistoryEntry.cpp

@@ -13,6 +13,8 @@
 #include "mozilla/dom/nsCSPContext.h"
 #include "mozilla/ipc/IPDLParamTraits.h"
 
+extern mozilla::LazyLogModule gSHLog;
+
 namespace mozilla {
 namespace dom {
 
@@ -264,6 +266,8 @@ LoadingSessionHistoryInfo::LoadingSessionHistoryInfo(
     SessionHistoryEntry::sLoadIdToEntry =
         new nsDataHashtable<nsUint64HashKey, SessionHistoryEntry*>();
   }
+  MOZ_LOG(gSHLog, LogLevel::Verbose,
+          ("SHEntry::AddLoadId(%" PRIu64 " - %p", mLoadId, aEntry));
   SessionHistoryEntry::sLoadIdToEntry->Put(mLoadId, aEntry);
 }
 
@@ -303,6 +307,8 @@ void SessionHistoryEntry::RemoveLoadId(uint64_t aLoadId) {
     return;
   }
 
+  MOZ_LOG(gSHLog, LogLevel::Verbose,
+          ("SHEntry::RemoveLoadId(%" PRIu64 ")", aLoadId));
   sLoadIdToEntry->Remove(aLoadId);
 }