From 4fa0e27ba39f49ba92fb4c160ab836a6f1dd2893 Mon Sep 17 00:00:00 2001 From: Lei Zhang Date: Thu, 8 Oct 2015 10:34:28 -0700 Subject: Relax the check on 0 length streams. CPDF_SyntaxParser::ReadStream() originally created stream objects when the length is 0. Commit 2526930 tightened the constraint and returned NULL. This has some adverse affects, as seen in Chromium's print preview of PDFs. Instead, relax the constraint a little so when the length is 0, return a CPDF_Stream with NULL data and size 0. BUG=531835 Review URL: https://codereview.chromium.org/1394743002 . --- .../src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp | 31 ++++++++++++---------- 1 file changed, 17 insertions(+), 14 deletions(-) (limited to 'core/src') diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp index 984e08d882..a94e5bb01d 100644 --- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp +++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp @@ -2521,28 +2521,31 @@ CPDF_Stream* CPDF_SyntaxParser::ReadStream(CPDF_Dictionary* pDict, len -= 1; } } - if (len <= 0) { + if (len < 0) { return nullptr; } pDict->SetAtInteger(FX_BSTRC("Length"), len); } m_Pos = streamStartPos; } - if (len <= 0) { + if (len < 0) { return nullptr; } - uint8_t* pData = FX_Alloc(uint8_t, len); - ReadBlock(pData, len); - if (pCryptoHandler) { - CFX_BinaryBuf dest_buf; - dest_buf.EstimateSize(pCryptoHandler->DecryptGetSize(len)); - void* context = pCryptoHandler->DecryptStart(objnum, gennum); - pCryptoHandler->DecryptStream(context, pData, len, dest_buf); - pCryptoHandler->DecryptFinish(context, dest_buf); - FX_Free(pData); - pData = dest_buf.GetBuffer(); - len = dest_buf.GetSize(); - dest_buf.DetachBuffer(); + uint8_t* pData = nullptr; + if (len > 0) { + pData = FX_Alloc(uint8_t, len); + ReadBlock(pData, len); + if (pCryptoHandler) { + CFX_BinaryBuf dest_buf; + dest_buf.EstimateSize(pCryptoHandler->DecryptGetSize(len)); + void* context = pCryptoHandler->DecryptStart(objnum, gennum); + pCryptoHandler->DecryptStream(context, pData, len, dest_buf); + pCryptoHandler->DecryptFinish(context, dest_buf); + FX_Free(pData); + pData = dest_buf.GetBuffer(); + len = dest_buf.GetSize(); + dest_buf.DetachBuffer(); + } } CPDF_Stream* pStream = new CPDF_Stream(pData, len, pDict); if (pContext) { -- cgit v1.2.3