Ensure that XFA Pages always have a corresponding PDF page

The PDF page may be blank, un-numbered, or untracked by CPDF, but
this provides a place for all XFA pages to "extend" from down the
road.

Change-Id: If1003be0f261154e61e9793ccba7e1f43cd73104
Reviewed-on: https://pdfium-review.googlesource.com/31771
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

4 files changed, 28 insertions, 57 deletions

diff --git a/fpdfsdk/fpdf_editpage.cpp b/fpdfsdk/fpdf_editpage.cpp
index 0647dc537f..f38c4ff800 100644
--- a/fpdfsdk/fpdf_editpage.cpp
+++ b/fpdfsdk/fpdf_editpage.cpp
@@ -182,7 +182,6 @@ FPDF_EXPORT FPDF_PAGE FPDF_CALLCONV FPDFPage_New(FPDF_DOCUMENT document,
   auto* pContext = static_cast<CPDFXFA_Context*>(pDoc->GetExtension());
   if (pContext) {
     auto pXFAPage = pdfium::MakeRetain<CPDFXFA_Page>(pContext, page_index);
-    pXFAPage->LoadPDFPage(pPageDict);
     return FPDFPageFromUnderlying(pXFAPage.Leak());  // Caller takes ownership.
   }
   // Eventually, fallthru into non-XFA case once page type is consistent.
diff --git a/fpdfsdk/fpdf_formfill.cpp b/fpdfsdk/fpdf_formfill.cpp
index 280ef62edb..c92fc7b718 100644
--- a/fpdfsdk/fpdf_formfill.cpp
+++ b/fpdfsdk/fpdf_formfill.cpp
@@ -621,7 +621,11 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_DoDocumentAAction(FPDF_FORMHANDLE hHandle,
   if (!pDict)
     return;
 
-  CPDF_AAction aa(pDict->GetDictFor("AA"));
+  CPDF_Dictionary* pActionDict = pDict->GetDictFor("AA");
+  if (!pActionDict)
+    return;
+
+  CPDF_AAction aa(pActionDict);
   auto type = static_cast<CPDF_AAction::AActionType>(aaType);
   if (aa.ActionExist(type)) {
     CPDF_Action action = aa.GetAction(type);
@@ -641,20 +645,22 @@ FPDF_EXPORT void FPDF_CALLCONV FORM_DoPageAAction(FPDF_PAGE page,
 
   UnderlyingPageType* pPage = UnderlyingFromFPDFPage(page);
   CPDF_Page* pPDFPage = CPDFPageFromFPDFPage(page);
-  if (!pPDFPage)
-    return;
-
-  if (!pFormFillEnv->GetPageView(pPage, false))
+  if (!pPDFPage || !pFormFillEnv->GetPageView(pPage, false))
     return;
 
   CPDFSDK_ActionHandler* pActionHandler = pFormFillEnv->GetActionHandler();
   CPDF_Dictionary* pPageDict = pPDFPage->m_pFormDict.Get();
-  CPDF_AAction aa(pPageDict->GetDictFor("AA"));
+  if (!pPageDict)
+    return;
+
+  CPDF_Dictionary* pActionDict = pPageDict->GetDictFor("AA");
+  if (!pActionDict)
+    return;
+
+  CPDF_AAction aa(pActionDict);
   CPDF_AAction::AActionType type = aaType == FPDFPAGE_AACTION_OPEN
                                        ? CPDF_AAction::OpenPage
                                        : CPDF_AAction::ClosePage;
-  if (aa.ActionExist(type)) {
-    CPDF_Action action = aa.GetAction(type);
-    pActionHandler->DoAction_Page(action, type, pFormFillEnv);
-  }
+  if (aa.ActionExist(type))
+    pActionHandler->DoAction_Page(aa.GetAction(type), type, pFormFillEnv);
 }
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
index 809214dec6..f1d7aa9ad3 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_page.cpp
@@ -18,32 +18,25 @@
 #include "xfa/fxfa/cxfa_ffpageview.h"
 
 CPDFXFA_Page::CPDFXFA_Page(CPDFXFA_Context* pContext, int page_index)
-    : m_pXFAPageView(nullptr), m_pContext(pContext), m_iPageIndex(page_index) {}
+    : m_pXFAPageView(nullptr), m_pContext(pContext), m_iPageIndex(page_index) {
+  CPDF_Document* pPDFDoc = m_pContext->GetPDFDoc();
+  CPDF_Dictionary* pDict = nullptr;
+  if (pPDFDoc && m_pContext->GetFormType() != FormType::kXFAFull)
+    pDict = pPDFDoc->GetPage(m_iPageIndex);
+  m_pPDFPage = pdfium::MakeUnique<CPDF_Page>(pPDFDoc, pDict, true);
+  m_pPDFPage->SetPageExtension(this);
+}
 
 CPDFXFA_Page::~CPDFXFA_Page() {}
 
-bool CPDFXFA_Page::LoadPDFPage() {
-  if (!m_pContext)
-    return false;
-
-  CPDF_Document* pPDFDoc = m_pContext->GetPDFDoc();
-  if (!pPDFDoc)
-    return false;
-
-  CPDF_Dictionary* pDict = pPDFDoc->GetPage(m_iPageIndex);
-  if (!pDict)
+bool CPDFXFA_Page::LoadPage() {
+  if (!m_pContext || m_iPageIndex < 0)
     return false;
 
-  if (!m_pPDFPage || m_pPDFPage->m_pFormDict != pDict) {
-    m_pPDFPage = pdfium::MakeUnique<CPDF_Page>(pPDFDoc, pDict, true);
+  if (m_pContext->GetFormType() != FormType::kXFAFull) {
     m_pPDFPage->ParseContent();
+    return true;
   }
-  return true;
-}
-
-bool CPDFXFA_Page::LoadXFAPageView() {
-  if (!m_pContext)
-    return false;
 
   CXFA_FFDoc* pXFADoc = m_pContext->GetXFADoc();
   if (!pXFADoc)
@@ -61,31 +54,6 @@ bool CPDFXFA_Page::LoadXFAPageView() {
   return true;
 }
 
-bool CPDFXFA_Page::LoadPage() {
-  if (!m_pContext || m_iPageIndex < 0)
-    return false;
-
-  switch (m_pContext->GetFormType()) {
-    case FormType::kNone:
-    case FormType::kAcroForm:
-    case FormType::kXFAForeground:
-      return LoadPDFPage();
-    case FormType::kXFAFull:
-      return LoadXFAPageView();
-  }
-  return false;
-}
-
-bool CPDFXFA_Page::LoadPDFPage(CPDF_Dictionary* pageDict) {
-  if (!m_pContext || m_iPageIndex < 0 || !pageDict)
-    return false;
-
-  m_pPDFPage =
-      pdfium::MakeUnique<CPDF_Page>(m_pContext->GetPDFDoc(), pageDict, true);
-  m_pPDFPage->ParseContent();
-  return true;
-}
-
 CPDF_Document::Extension* CPDFXFA_Page::GetDocumentExtension() const {
   return m_pContext.Get();
 }
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_page.h b/fpdfsdk/fpdfxfa/cpdfxfa_page.h
index 4f4d6b0a22..faacf3e0b0 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_page.h
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_page.h
@@ -27,7 +27,6 @@ class CPDFXFA_Page : public CPDF_Page::Extension {
   friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
   bool LoadPage();
-  bool LoadPDFPage(CPDF_Dictionary* pageDict);
 
   // CPDF_Page::Extension:
   CPDF_Document::Extension* GetDocumentExtension() const override;
@@ -57,7 +56,6 @@ class CPDFXFA_Page : public CPDF_Page::Extension {
   CPDFXFA_Page(CPDFXFA_Context* pContext, int page_index);
   ~CPDFXFA_Page() override;
 
-  bool LoadPDFPage();
   bool LoadXFAPageView();
 
  private: