Disable JavaScript entirely if no JSPlatform passed by embedder.

Allows run-time selection of whether to permit JS inside PDF. Previously,
this was a link-time decision only. This requires a little more caution
before we decide that we have the CJS_Runtime, and not the CJS_RuntimeStub
in a few casts.

Adds a kDisableJavaScript option to the form fill embeddertests.
Adds a --disable-javascript flag to the pdfium_test executable.
Also adds a --disable-xfa flag while we're at it.

Change-Id: I8d8ac95f6474459cadba9a60572fbb342e984646
Reviewed-on: https://pdfium-review.googlesource.com/31090
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

3 files changed, 39 insertions, 8 deletions

diff --git a/fpdfsdk/cpdfsdk_formfillenvironment.cpp b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
index b3375d4501..272e27032b 100644
--- a/fpdfsdk/cpdfsdk_formfillenvironment.cpp
+++ b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
@@ -203,8 +203,6 @@ void CPDFSDK_FormFillEnvironment::JS_docgotoPage(int nPageNum) {
 }
 
 IJS_Runtime* CPDFSDK_FormFillEnvironment::GetIJSRuntime() {
-  if (!IsJSPlatformPresent())
-    return nullptr;
   if (!m_pIJSRuntime)
     m_pIJSRuntime = IJS_Runtime::Create(this);
   return m_pIJSRuntime.get();
diff --git a/fpdfsdk/fpdf_formfill_embeddertest.cpp b/fpdfsdk/fpdf_formfill_embeddertest.cpp
index 09e0c200d3..cedb96c0ca 100644
--- a/fpdfsdk/fpdf_formfill_embeddertest.cpp
+++ b/fpdfsdk/fpdf_formfill_embeddertest.cpp
@@ -380,6 +380,36 @@ TEST_F(FPDFFormFillEmbeddertest, BUG_514690) {
 }
 
 #ifdef PDF_ENABLE_V8
+TEST_F(FPDFFormFillEmbeddertest, DisableJavaScript) {
+  // Test that timers and intervals can't fire without JS.
+  EmbedderTestTimerHandlingDelegate delegate;
+  SetDelegate(&delegate);
+
+  EXPECT_TRUE(OpenDocumentWithoutJavaScript("bug_551248.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_TRUE(page);
+  DoOpenActions();
+
+  const auto& alerts = delegate.GetAlerts();
+  EXPECT_EQ(0U, alerts.size());
+
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  delegate.AdvanceTime(1000);
+  EXPECT_EQ(0U, alerts.size());  // nothing fired.
+  UnloadPage(page);
+}
+
 TEST_F(FPDFFormFillEmbeddertest, BUG_551248) {
   // Test that timers fire once and intervals fire repeatedly.
   EmbedderTestTimerHandlingDelegate delegate;
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_context.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_context.cpp
index c85c1bd27e..7d1b28be70 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_context.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_context.cpp
@@ -81,11 +81,11 @@ void CPDFXFA_Context::SetFormFillEnv(
 
 bool CPDFXFA_Context::LoadXFADoc() {
   m_nLoadStatus = FXFA_LOADSTATUS_LOADING;
+  m_XFAPageList.clear();
+
   if (!m_pPDFDoc)
     return false;
 
-  m_XFAPageList.clear();
-
   CXFA_FFApp* pApp = GetXFAApp();
   if (!pApp)
     return false;
@@ -96,8 +96,13 @@ bool CPDFXFA_Context::LoadXFADoc() {
     return false;
   }
 
-  m_pXFADoc->GetXFADoc()->InitScriptContext(GetCJSRuntime());
+  CJS_Runtime* actual_runtime = GetCJSRuntime();  // Null if a stub.
+  if (!actual_runtime) {
+    SetLastError(FPDF_ERR_XFALOAD);
+    return false;
+  }
 
+  m_pXFADoc->GetXFADoc()->InitScriptContext(actual_runtime);
   if (m_pXFADoc->GetFormType() == FormType::kXFAFull)
     m_FormType = FormType::kXFAFull;
   else
@@ -113,7 +118,6 @@ bool CPDFXFA_Context::LoadXFADoc() {
   m_pXFADocView->DoLayout();
   m_pXFADocView->StopLayout();
   m_nLoadStatus = FXFA_LOADSTATUS_LOADED;
-
   return true;
 }
 
@@ -196,8 +200,7 @@ CJS_Runtime* CPDFXFA_Context::GetCJSRuntime() const {
   if (!m_pFormFillEnv)
     return nullptr;
 
-  // XFA requires V8, if we have V8 then we have a CJS_Runtime and not the stub.
-  return static_cast<CJS_Runtime*>(m_pFormFillEnv->GetIJSRuntime());
+  return m_pFormFillEnv->GetIJSRuntime()->AsCJSRuntime();
 }
 
 WideString CPDFXFA_Context::GetAppTitle() const {