Bug 1689601, make it possible to call Document::CanSavePresentation non-recursively, r=peterv

Differential Revision: https://phabricator.services.mozilla.com/D105236

docshell/base/nsDocShell.cpp

@@ -6938,7 +6938,7 @@ bool nsDocShell::CanSavePresentation(uint32_t aLoadType,
 
   uint16_t bfCacheCombo = 0;
   bool canSavePresentation =
-      doc->CanSavePresentation(aNewRequest, bfCacheCombo);
+      doc->CanSavePresentation(aNewRequest, bfCacheCombo, true);
   MOZ_ASSERT_IF(canSavePresentation, bfCacheCombo == 0);
   if (canSavePresentation && doc->IsTopLevelContentDocument()) {
     auto* browsingContextGroup = mBrowsingContext->Group();

dom/base/Document.cpp

@@ -10634,7 +10634,8 @@ void Document::CollectDescendantDocuments(
 }
 
 bool Document::CanSavePresentation(nsIRequest* aNewRequest,
-                                   uint16_t& aBFCacheCombo) {
+                                   uint16_t& aBFCacheCombo,
+                                   bool aIncludeSubdocuments) {
   bool ret = true;
 
   if (!IsBFCachingAllowed()) {
@@ -10763,16 +10764,16 @@ bool Document::CanSavePresentation(nsIRequest* aNewRequest,
     ret = false;
   }
 
-  if (mSubDocuments) {
+  if (aIncludeSubdocuments && mSubDocuments) {
     for (auto iter = mSubDocuments->Iter(); !iter.Done(); iter.Next()) {
       auto entry = static_cast<SubDocMapEntry*>(iter.Get());
       Document* subdoc = entry->mSubDocument;
 
       uint16_t subDocBFCacheCombo = 0;
       // The aIgnoreRequest we were passed is only for us, so don't pass it on.
-      bool canCache =
-          subdoc ? subdoc->CanSavePresentation(nullptr, subDocBFCacheCombo)
-                 : false;
+      bool canCache = subdoc ? subdoc->CanSavePresentation(
+                                   nullptr, subDocBFCacheCombo, true)
+                             : false;
       if (!canCache) {
         MOZ_LOG(gPageCacheLog, mozilla::LogLevel::Verbose,
                 ("Save of %s blocked due to subdocument blocked", uri.get()));

dom/base/Document.h

@@ -2319,8 +2319,8 @@ class Document : public nsINode,
 
   /**
    * Check whether it is safe to cache the presentation of this document
-   * and all of its subdocuments. This method checks the following conditions
-   * recursively:
+   * and all of its subdocuments (depending on the 3rd param). This method
+   * checks the following conditions recursively:
    *  - Some document types, such as plugin documents, cannot be safely cached.
    *  - If there are any pending requests, we don't allow the presentation
    *    to be cached.  Ideally these requests would be suspended and resumed,
@@ -2338,7 +2338,8 @@ class Document : public nsINode,
    * combination is when we try to BFCache aNewRequest
    */
   virtual bool CanSavePresentation(nsIRequest* aNewRequest,
-                                   uint16_t& aBFCacheCombo);
+                                   uint16_t& aBFCacheCombo,
+                                   bool aIncludeSubdocuments);
 
   virtual nsresult Init();
 

dom/html/PluginDocument.cpp

@@ -39,8 +39,8 @@ class PluginDocument final : public MediaDocument, public nsIPluginDocument {
 
   void SetScriptGlobalObject(
       nsIScriptGlobalObject* aScriptGlobalObject) override;
-  bool CanSavePresentation(nsIRequest* aNewRequest,
-                           uint16_t& aBFCacheStatus) override;
+  bool CanSavePresentation(nsIRequest* aNewRequest, uint16_t& aBFCacheStatus,
+                           bool aIncludeSubdocuments = true) override;
 
   const nsCString& GetType() const { return mMimeType; }
   Element* GetPluginContent() { return mPluginContent; }
@@ -135,7 +135,8 @@ void PluginDocument::SetScriptGlobalObject(
 }
 
 bool PluginDocument::CanSavePresentation(nsIRequest* aNewRequest,
-                                         uint16_t& aBFCacheStatus) {
+                                         uint16_t& aBFCacheStatus,
+                                         bool aIncludeSubdocuments) {
   // Full-page plugins cannot be cached, currently, because we don't have
   // the stream listener data to feed to the plugin instance.
   return false;