Fix crash in _CMapLookupCallback

core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp

Index: core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
index bd8b157bfa9590a8a095f8782dd958e333b70d51..cdfcc976090a38be79c048bfba73681e54b1a6b0 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
@@ -1330,7 +1330,7 @@ void CPDF_IndirectObjects::InsertIndirectObject(FX_DWORD objnum, CPDF_Object* pO
     }
     FX_LPVOID value;
     if (m_IndirectObjs.Lookup((FX_LPVOID)(FX_UINTPTR)objnum, value)) {
-        ((CPDF_Object*)value)->Destroy();
+        return;

[palmer, 2014/06/25 23:21:44]

But the caller is going to expect that this function succeeded in updating
|pObj|, right? Is this fix going to cause other breakage (other crashes, PDF
semantics violations)?

     }
     pObj->m_ObjNum = objnum;
     m_IndirectObjs.SetAt((FX_LPVOID)(FX_UINTPTR)objnum, pObj);