Fix the issue 'SEGV on unknown address in CPDF_DataAvail::GetObjectSize'

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp

Index: core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index e0fd3bfaeecea13e1b023d68982f3d35897ff2b9..4dcaa5a94f6914c04d7c40323c5308a966a99627 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -4114,12 +4114,13 @@ FX_BOOL CPDF_DataAvail::CheckLinearizedData(IFX_DownloadHints* pHints)
     FX_DWORD dwRet = 0;
     if (!m_bMainXRefLoad) {

[Tom Sepez, 2014/08/09 17:55:36]

does m_bMainXRefLoad mean "main xref load succeeded" or "main xref load was
tried once already"?  I think its the later, and if so, the name should be
m_bMainXrefLoadTried.

[jun_fang, 2014/08/18 06:58:00]

if |m_bMainXRefLoad| is true, it means that xref is loaded successfully not the
second meaning you mentioned.

[palmer, 2014/08/19 20:26:41]

In that case, I would call it |m_bMainXRefLoadSucceeded|.

         dwRet = ((CPDF_Parser *)m_pDocument->GetParser())->LoadLinearizedMainXRefTable();
-        if (dwRet == PDFPARSE_ERROR_SUCCESS) {
-            if (!PreparePageItem()) {
-                return FALSE;
-            }
-            m_bMainXRefLoadedOK = TRUE;
+        if (dwRet != PDFPARSE_ERROR_SUCCESS) {
+            return FALSE;
+        }
+        if (!PreparePageItem()) {
+            return FALSE;
         }
+        m_bMainXRefLoadedOK = TRUE;

[Tom Sepez, 2014/08/09 17:55:36]

What's the difference between m_bMainXrefLoadedOK and m_bLinearizedDataOK?  Is
it ever the case that one is true without the other?

[jun_fang, 2014/08/18 06:58:00]

They are different. |m_bMainXrefLoadedOK is true| means that XRef table is
loaded successfully. |m_bLinearizedDataOK is true| means that data are
downloaded and available for being parsed.

[palmer, 2014/08/19 20:26:41]

Wait, then what does |m_bMainXRefLoad| mean that is distinct from
|m_bMainXRefLoadedOK|?

         m_bMainXRefLoad = TRUE;
     }
     m_bLinearedDataOK = TRUE;