Segv when PDF-side JS object property getter invoked from XFA.

The PDF-side native objects require that the current v8 context
has been set-up to point at the state (via CJS_Runtime) for the
getters, setters, and methods to operate against. XFA doesn't
supply a context with that state, so at the first opportunity for
a PDF-side object to be leaked to XFA, set up the context to mimic
the PDF side.

Changed FXJS_GetRuntimeFromIsolate() to FXJS_GetRuntimeFromV8Context()
for consistency with the newly added method.

BUG=pdfium:266
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/1412103010 .

1 files changed, 8 insertions, 4 deletions

diff --git a/fpdfsdk/src/jsapi/fxjs_v8.cpp b/fpdfsdk/src/jsapi/fxjs_v8.cpp
index 2ff515d0ab..3413d72bb3 100644
--- a/fpdfsdk/src/jsapi/fxjs_v8.cpp
+++ b/fpdfsdk/src/jsapi/fxjs_v8.cpp
@@ -287,7 +287,7 @@ void FXJS_InitializeRuntime(v8::Isolate* pIsolate,
   v8::Context::Scope context_scope(v8Context);
 
   FXJS_PerIsolateData::SetUp(pIsolate);
-  v8Context->SetAlignedPointerInEmbedderData(kPerContextDataIndex, pIRuntime);
+  FXJS_SetRuntimeForV8Context(v8Context, pIRuntime);
 
   int maxID = CFXJS_ObjDefinition::MaxID(pIsolate);
   for (int i = 0; i < maxID; ++i) {
@@ -361,10 +361,14 @@ void FXJS_ReleaseRuntime(v8::Isolate* pIsolate,
   delete pData;
 }
 
-IJS_Runtime* FXJS_GetRuntimeFromIsolate(v8::Isolate* pIsolate) {
-  v8::Local<v8::Context> context = pIsolate->GetCurrentContext();
+void FXJS_SetRuntimeForV8Context(v8::Local<v8::Context> v8Context,
+                                 IJS_Runtime* pIRuntime) {
+  v8Context->SetAlignedPointerInEmbedderData(kPerContextDataIndex, pIRuntime);
+}
+
+IJS_Runtime* FXJS_GetRuntimeFromV8Context(v8::Local<v8::Context> v8Context) {
   return static_cast<IJS_Runtime*>(
-      context->GetAlignedPointerFromEmbedderData(kPerContextDataIndex));
+      v8Context->GetAlignedPointerFromEmbedderData(kPerContextDataIndex));
 }
 
 int FXJS_Execute(v8::Isolate* pIsolate,