Add unit test for CXFA_FileRead.

The FileRead's return convention is being modified at
https://codereview.chromium.org/2430743003/, so first provide
a test of the old behaviour.

Fix some issues with null dictionaries as provided by the
CPDF_Stream default ctor along the way.

Review-Url: https://codereview.chromium.org/2517513003

6 files changed, 116 insertions, 30 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 8c520182b8..be9ced7cee 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1743,6 +1743,7 @@ test("pdfium_unittests") {
       "xfa/fde/css/fde_cssdatatable_unittest.cpp",
       "xfa/fde/xml/fde_xml_imp_unittest.cpp",
       "xfa/fxbarcode/pdf417/BC_PDF417HighLevelEncoder_unittest.cpp",
+      "xfa/fxfa/app/xfa_ffapp_unittest.cpp",
       "xfa/fxfa/app/xfa_textlayout_unittest.cpp",
       "xfa/fxfa/fm2js/xfa_simpleexpression_unittest.cpp",
       "xfa/fxfa/parser/xfa_utils_unittest.cpp",
diff --git a/core/fpdfapi/edit/fpdf_edit_create.cpp b/core/fpdfapi/edit/fpdf_edit_create.cpp
index ff12606399..360472948d 100644
--- a/core/fpdfapi/edit/fpdf_edit_create.cpp
+++ b/core/fpdfapi/edit/fpdf_edit_create.cpp
@@ -417,26 +417,24 @@ CPDF_FlateEncoder::CPDF_FlateEncoder(CPDF_Stream* pStream, bool bFlateEncode)
       m_bCloned(false),
       m_bNewData(false) {
   m_Acc.LoadAllData(pStream, true);
-  if ((pStream && pStream->GetDict() &&
-       pStream->GetDict()->KeyExist("Filter")) ||
-      !bFlateEncode) {
-    if (pStream->GetDict()->KeyExist("Filter") && !bFlateEncode) {
-      CPDF_StreamAcc destAcc;
-      destAcc.LoadAllData(pStream);
-      m_dwSize = destAcc.GetSize();
-      m_pData = (uint8_t*)destAcc.DetachData();
-      m_pDict = ToDictionary(pStream->GetDict()->Clone().release());
-      m_pDict->RemoveFor("Filter");
-      m_bNewData = true;
-      m_bCloned = true;
-    } else {
-      m_pData = (uint8_t*)m_Acc.GetData();
-      m_dwSize = m_Acc.GetSize();
-      m_pDict = pStream->GetDict();
-    }
+  bool bHasFilter = pStream && pStream->HasFilter();
+  if (bHasFilter && !bFlateEncode) {
+    CPDF_StreamAcc destAcc;
+    destAcc.LoadAllData(pStream);
+    m_dwSize = destAcc.GetSize();
+    m_pData = (uint8_t*)destAcc.DetachData();
+    m_pDict = ToDictionary(pStream->GetDict()->Clone().release());
+    m_pDict->RemoveFor("Filter");
+    m_bNewData = true;
+    m_bCloned = true;
+    return;
+  }
+  if (bHasFilter || !bFlateEncode) {
+    m_pData = (uint8_t*)m_Acc.GetData();
+    m_dwSize = m_Acc.GetSize();
+    m_pDict = pStream->GetDict();
     return;
   }
-
   m_bNewData = true;
   m_bCloned = true;
   // TODO(thestig): Move to Init() and check return value.
diff --git a/core/fpdfapi/parser/cpdf_stream.cpp b/core/fpdfapi/parser/cpdf_stream.cpp
index e8ee022940..64261b14d3 100644
--- a/core/fpdfapi/parser/cpdf_stream.cpp
+++ b/core/fpdfapi/parser/cpdf_stream.cpp
@@ -113,6 +113,10 @@ bool CPDF_Stream::ReadRawData(FX_FILESIZE offset,
   return true;
 }
 
+bool CPDF_Stream::HasFilter() const {
+  return m_pDict && m_pDict->KeyExist("Filter");
+}
+
 CFX_WideString CPDF_Stream::GetUnicodeText() const {
   CPDF_StreamAcc stream;
   stream.LoadAllData(this, false);
diff --git a/core/fpdfapi/parser/cpdf_stream.h b/core/fpdfapi/parser/cpdf_stream.h
index ddf7cc5b69..c4f9aacf2b 100644
--- a/core/fpdfapi/parser/cpdf_stream.h
+++ b/core/fpdfapi/parser/cpdf_stream.h
@@ -46,6 +46,7 @@ class CPDF_Stream : public CPDF_Object {
                    uint32_t buf_size) const;
 
   bool IsMemoryBased() const { return m_bMemoryBased; }
+  bool HasFilter() const;
 
  protected:
   std::unique_ptr<CPDF_Object> CloneNonCyclic(
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.cpp b/core/fpdfapi/parser/cpdf_stream_acc.cpp
index 81439bc677..01d8e148df 100644
--- a/core/fpdfapi/parser/cpdf_stream_acc.cpp
+++ b/core/fpdfapi/parser/cpdf_stream_acc.cpp
@@ -24,17 +24,16 @@ void CPDF_StreamAcc::LoadAllData(const CPDF_Stream* pStream,
     return;
 
   m_pStream = pStream;
-  if (pStream->IsMemoryBased() &&
-      (!pStream->GetDict()->KeyExist("Filter") || bRawAccess)) {
+  if (pStream->IsMemoryBased() && (!pStream->HasFilter() || bRawAccess)) {
     m_dwSize = pStream->GetRawSize();
     m_pData = pStream->GetRawData();
     return;
   }
-  uint8_t* pSrcData;
   uint32_t dwSrcSize = pStream->GetRawSize();
   if (dwSrcSize == 0)
     return;
 
+  uint8_t* pSrcData;
   if (!pStream->IsMemoryBased()) {
     pSrcData = m_pSrcData = FX_Alloc(uint8_t, dwSrcSize);
     if (!pStream->ReadRawData(0, pSrcData, dwSrcSize))
@@ -42,17 +41,14 @@ void CPDF_StreamAcc::LoadAllData(const CPDF_Stream* pStream,
   } else {
     pSrcData = pStream->GetRawData();
   }
-  if (!pStream->GetDict()->KeyExist("Filter") || bRawAccess) {
+  if (!pStream->HasFilter() || bRawAccess) {
+    m_pData = pSrcData;
+    m_dwSize = dwSrcSize;
+  } else if (!PDF_DataDecode(pSrcData, dwSrcSize, m_pStream->GetDict(), m_pData,
+                             m_dwSize, m_ImageDecoder, m_pImageParam,
+                             estimated_size, bImageAcc)) {
     m_pData = pSrcData;
     m_dwSize = dwSrcSize;
-  } else {
-    bool bRet = PDF_DataDecode(pSrcData, dwSrcSize, m_pStream->GetDict(),
-                               m_pData, m_dwSize, m_ImageDecoder, m_pImageParam,
-                               estimated_size, bImageAcc);
-    if (!bRet) {
-      m_pData = pSrcData;
-      m_dwSize = dwSrcSize;
-    }
   }
   if (pSrcData != pStream->GetRawData() && pSrcData != m_pData)
     FX_Free(pSrcData);
diff --git a/xfa/fxfa/app/xfa_ffapp_unittest.cpp b/xfa/fxfa/app/xfa_ffapp_unittest.cpp
new file mode 100644
index 0000000000..7e1b9d7237
--- /dev/null
+++ b/xfa/fxfa/app/xfa_ffapp_unittest.cpp
@@ -0,0 +1,86 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "xfa/fxfa/xfa_ffapp.h"
+
+#include <memory>
+
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fxcrt/fx_memory.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/base/ptr_util.h"
+
+using UniqueFileRead =
+    std::unique_ptr<CXFA_FileRead, ReleaseDeleter<CXFA_FileRead>>;
+
+TEST(CXFAFileRead, NoStreams) {
+  std::vector<CPDF_Stream*> streams;
+  UniqueFileRead fileread(new CXFA_FileRead(streams));
+
+  uint8_t output_buffer[16];
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_FALSE(fileread->ReadBlock(output_buffer, 0, 0));
+  EXPECT_EQ(0xbd, output_buffer[0]);
+}
+
+TEST(CXFAFileRead, EmptyStreams) {
+  std::vector<CPDF_Stream*> streams;
+  std::unique_ptr<CPDF_Stream> stream1 = pdfium::MakeUnique<CPDF_Stream>();
+  streams.push_back(stream1.get());
+  UniqueFileRead fileread(new CXFA_FileRead(streams));
+
+  uint8_t output_buffer[16];
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_FALSE(fileread->ReadBlock(output_buffer, 0, 0));
+  EXPECT_EQ(0xbd, output_buffer[0]);
+}
+
+TEST(CXFAFileRead, NormalStreams) {
+  std::vector<CPDF_Stream*> streams;
+  std::unique_ptr<CPDF_Stream> stream1 = pdfium::MakeUnique<CPDF_Stream>();
+  std::unique_ptr<CPDF_Stream> stream2 = pdfium::MakeUnique<CPDF_Stream>();
+  std::unique_ptr<CPDF_Stream> stream3 = pdfium::MakeUnique<CPDF_Stream>();
+
+  // 16 chars total.
+  stream1->InitStream(reinterpret_cast<const uint8_t*>("one t"), 5,
+                      new CPDF_Dictionary());
+  stream2->InitStream(reinterpret_cast<const uint8_t*>("wo "), 3,
+                      new CPDF_Dictionary());
+  stream3->InitStream(reinterpret_cast<const uint8_t*>("three!!!"), 8,
+                      new CPDF_Dictionary());
+
+  streams.push_back(stream1.get());
+  streams.push_back(stream2.get());
+  streams.push_back(stream3.get());
+  UniqueFileRead fileread(new CXFA_FileRead(streams));
+
+  uint8_t output_buffer[16];
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_TRUE(fileread->ReadBlock(output_buffer, 0, 0));
+  EXPECT_EQ(0xbd, output_buffer[0]);
+
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_TRUE(fileread->ReadBlock(output_buffer, 1, 0));
+  EXPECT_EQ(0xbd, output_buffer[0]);
+
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_TRUE(fileread->ReadBlock(output_buffer, 0, 1));
+  EXPECT_EQ(0, memcmp(output_buffer, "o", 1));
+  EXPECT_EQ(0xbd, output_buffer[1]);
+
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_TRUE(fileread->ReadBlock(output_buffer, 0, sizeof(output_buffer)));
+  EXPECT_EQ(0, memcmp(output_buffer, "one two three!!!", 16));
+
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_TRUE(fileread->ReadBlock(output_buffer, 2, 10));
+  EXPECT_EQ(0, memcmp(output_buffer, "e two thre", 10));
+  EXPECT_EQ(0xbd, output_buffer[11]);
+
+  memset(output_buffer, 0xbd, sizeof(output_buffer));
+  EXPECT_FALSE(fileread->ReadBlock(output_buffer, 1, sizeof(output_buffer)));
+  EXPECT_EQ(0, memcmp(output_buffer, "ne two three!!!", 15));
+  EXPECT_EQ(0xbd, output_buffer[15]);
+}