commit 7dc6b1b652fc2c53456631d5a3a612af140056dc
author Tom Sepez <tsepez@chromium.org> Fri Feb 15 18:13:23 2019 +0000
committer Chromium commit bot <commit-bot@chromium.org> Fri Feb 15 18:13:23 2019 +0000
tree 3b43f784f99ce50461b6adb25f61666ab1447cbe
parent 8587173d1069e0cf35c07e9987bcd0f1d391b52a

CJX_Xfa::thisValue() can be null when called from C++.

It won't be NULL when called from JS, but it may be directly
invoked on top of CXFA_Document::DoProtoMerge() without first
establishing a binding for |xfa.this|.

Bug: pdfium:1238
Change-Id: I91bf83a38f42ff2bde3077190e069168d1c937dd
Reviewed-on: https://pdfium-review.googlesource.com/c/50910
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

fxjs/xfa/cjx_xfa.cpp

diff --git a/fxjs/xfa/cjx_xfa.cpp b/fxjs/xfa/cjx_xfa.cpp
index 7de690f..2d943bd 100644
--- a/fxjs/xfa/cjx_xfa.cpp
+++ b/fxjs/xfa/cjx_xfa.cpp
@@ -25,7 +25,11 @@
   if (bSetting)
     return;
 
-  CXFA_Object* pThis = GetDocument()->GetScriptContext()->GetThisObject();
-  ASSERT(pThis);
-  pValue->Assign(GetDocument()->GetScriptContext()->GetJSValueFromMap(pThis));
+  auto* pScriptContext = GetDocument()->GetScriptContext();
+  CXFA_Object* pThis = pScriptContext->GetThisObject();
+  if (!pThis) {
+    pValue->SetNull();
+    return;
+  }
+  pValue->Assign(pScriptContext->GetJSValueFromMap(pThis));
 }