Bug 1696266, limit the load types which may cause the page to enter bfcache, r=peterv

The change to dom/base/nsFrameLoaderOwner.cpp is to log about the issues but still ensure we don't crash.

I'd prefer to not put error loads to bfcache.

Differential Revision: https://phabricator.services.mozilla.com/D107300

docshell/base/nsDocShell.cpp

@@ -6951,7 +6951,6 @@ bool nsDocShell::CanSavePresentation(uint32_t aLoadType,
   // Only save presentation for "normal" loads and link loads.  Anything else
   // probably wants to refetch the page, so caching the old presentation
   // would be incorrect.
-  // XXXBFCache in parent needs something like this!
   if (aLoadType != LOAD_NORMAL && aLoadType != LOAD_HISTORY &&
       aLoadType != LOAD_LINK && aLoadType != LOAD_STOP_CONTENT &&
       aLoadType != LOAD_STOP_CONTENT_AND_REPLACE &&

dom/base/nsFrameLoaderOwner.cpp

@@ -142,6 +142,18 @@ void nsFrameLoaderOwner::ChangeRemotenessCommon(
                 ("nsFrameLoaderOwner::ChangeRemotenessCommon: store the old "
                  "page in bfcache"));
             Unused << bc->SetIsInBFCache(true);
+            if (she->GetFrameLoader()) {
+              MOZ_LOG(gSHIPBFCacheLog, LogLevel::Debug,
+                      ("nsFrameLoaderOwner::ChangeRemotenessCommon: active "
+                       "session history entry "
+                       "has already an nsFrameLoader!, FIXME"));
+              MOZ_DIAGNOSTIC_ASSERT(false,
+                                    "The current session history entry has "
+                                    "already an nsFrameLoader!");
+              RefPtr<nsFrameLoader> oldFrameLoader = she->GetFrameLoader();
+              she->SetFrameLoader(nullptr);
+              oldFrameLoader->Destroy();
+            }
             she->SetFrameLoader(mFrameLoader);
             // Session history owns now the frameloader.
             mFrameLoader = nullptr;

netwerk/ipc/DocumentLoadListener.cpp

@@ -1631,7 +1631,10 @@ bool DocumentLoadListener::MaybeTriggerProcessSwitch(
       browsingContext->Group()->Toplevels().Length() == 1 &&
       !options.mRemoteType.IsEmpty() &&
       browsingContext->GetHasLoadedNonInitialDocument() &&
-      mLoadStateLoadType != LOAD_ERROR_PAGE) {
+      (mLoadStateLoadType == LOAD_NORMAL ||
+       mLoadStateLoadType == LOAD_HISTORY || mLoadStateLoadType == LOAD_LINK ||
+       mLoadStateLoadType == LOAD_STOP_CONTENT ||
+       mLoadStateLoadType == LOAD_STOP_CONTENT_AND_REPLACE)) {
     options.mReplaceBrowsingContext = true;
     options.mTryUseBFCache = true;
   }