Make flate decode functions' buffer out parameter unique_ptrs.

Change-Id: Idb14846e87a8287dd911b0a2f7a32146e86c2af7
Reviewed-on: https://pdfium-review.googlesource.com/41853
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

4 files changed, 18 insertions, 13 deletions

diff --git a/core/fpdfapi/page/cpdf_streamparser.cpp b/core/fpdfapi/page/cpdf_streamparser.cpp
index 69205cb934..88b3993327 100644
--- a/core/fpdfapi/page/cpdf_streamparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamparser.cpp
@@ -70,12 +70,15 @@ uint32_t DecodeInlineStream(pdfium::span<const uint8_t> src_span,
                             uint32_t* dest_size) {
   *dest_buf = nullptr;
   *dest_size = 0;
+  std::unique_ptr<uint8_t, FxFreeDeleter> ignored_result;
   if (decoder == "FlateDecode" || decoder == "Fl") {
-    return FlateOrLZWDecode(false, src_span, pParam, *dest_size, dest_buf,
+    return FlateOrLZWDecode(false, src_span, pParam, *dest_size,
+                            &ignored_result, dest_size);
+  }
+  if (decoder == "LZWDecode" || decoder == "LZW") {
+    return FlateOrLZWDecode(true, src_span, pParam, 0, &ignored_result,
                             dest_size);
   }
-  if (decoder == "LZWDecode" || decoder == "LZW")
-    return FlateOrLZWDecode(true, src_span, pParam, 0, dest_buf, dest_size);
   if (decoder == "DCTDecode" || decoder == "DCT") {
     std::unique_ptr<CCodec_ScanlineDecoder> pDecoder =
         CPDF_ModuleMgr::Get()->GetJpegModule()->CreateDecoder(
@@ -89,7 +92,6 @@ uint32_t DecodeInlineStream(pdfium::span<const uint8_t> src_span,
     return DecodeAllScanlines(std::move(pDecoder), dest_buf, dest_size);
   }
 
-  std::unique_ptr<uint8_t, FxFreeDeleter> ignored_result;
   if (decoder == "ASCII85Decode" || decoder == "A85")
     return A85Decode(src_span, &ignored_result, dest_size);
   if (decoder == "ASCIIHexDecode" || decoder == "AHx")
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.cpp b/core/fpdfapi/parser/fpdf_parser_decode.cpp
index 9041666c07..eafb8ee8a3 100644
--- a/core/fpdfapi/parser/fpdf_parser_decode.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_decode.cpp
@@ -320,7 +320,7 @@ uint32_t FlateOrLZWDecode(bool bLZW,
                           pdfium::span<const uint8_t> src_span,
                           const CPDF_Dictionary* pParams,
                           uint32_t estimated_size,
-                          uint8_t** dest_buf,
+                          std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
                           uint32_t* dest_size) {
   int predictor = 0;
   int Colors = 0;
@@ -389,11 +389,15 @@ bool PDF_DataDecode(pdfium::span<const uint8_t> src_span,
         *pImageParams = pParam;
         return true;
       }
+      std::unique_ptr<uint8_t, FxFreeDeleter> result;
       offset = FlateOrLZWDecode(false, last_span, pParam, estimated_size,
-                                &new_buf, &new_size);
+                                &result, &new_size);
+      new_buf = result.release();
     } else if (decoder == "LZWDecode" || decoder == "LZW") {
+      std::unique_ptr<uint8_t, FxFreeDeleter> result;
       offset = FlateOrLZWDecode(true, last_span, pParam, estimated_size,
-                                &new_buf, &new_size);
+                                &result, &new_size);
+      new_buf = result.release();
     } else if (decoder == "ASCII85Decode" || decoder == "A85") {
       std::unique_ptr<uint8_t, FxFreeDeleter> result;
       offset = A85Decode(last_span, &result, &new_size);
@@ -578,7 +582,7 @@ bool FlateEncode(pdfium::span<const uint8_t> src_span,
 }
 
 uint32_t FlateDecode(pdfium::span<const uint8_t> src_span,
-                     uint8_t** dest_buf,
+                     std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
                      uint32_t* dest_size) {
   CCodec_ModuleMgr* pEncoders = CPDF_ModuleMgr::Get()->GetCodecModule();
   return pEncoders->GetFlateModule()->FlateOrLZWDecode(
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.h b/core/fpdfapi/parser/fpdf_parser_decode.h
index 0032b97423..e4fdce1037 100644
--- a/core/fpdfapi/parser/fpdf_parser_decode.h
+++ b/core/fpdfapi/parser/fpdf_parser_decode.h
@@ -44,7 +44,7 @@ bool FlateEncode(pdfium::span<const uint8_t> src_span,
                  uint32_t* dest_size);
 
 uint32_t FlateDecode(pdfium::span<const uint8_t> src_span,
-                     uint8_t** dest_buf,
+                     std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
                      uint32_t* dest_size);
 
 uint32_t RunLengthDecode(pdfium::span<const uint8_t> src_span,
@@ -63,7 +63,7 @@ uint32_t FlateOrLZWDecode(bool bLZW,
                           pdfium::span<const uint8_t> src_span,
                           const CPDF_Dictionary* pParams,
                           uint32_t estimated_size,
-                          uint8_t** dest_buf,
+                          std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
                           uint32_t* dest_size);
 
 bool PDF_DataDecode(pdfium::span<const uint8_t> src_span,
diff --git a/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp b/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp
index d7256f0da5..94776e17ea 100644
--- a/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp
@@ -74,7 +74,7 @@ TEST_F(FPDFParserDecodeEmbeddertest, FlateDecode) {
 
   for (size_t i = 0; i < FX_ArraySize(flate_decode_cases); ++i) {
     const pdfium::DecodeTestData& data = flate_decode_cases[i];
-    unsigned char* buf = nullptr;
+    std::unique_ptr<uint8_t, FxFreeDeleter> buf;
     uint32_t buf_size;
     EXPECT_EQ(data.processed_size,
               FlateDecode({data.input, data.input_size}, &buf, &buf_size))
@@ -83,9 +83,8 @@ TEST_F(FPDFParserDecodeEmbeddertest, FlateDecode) {
     EXPECT_EQ(data.expected_size, buf_size) << " for case " << i;
     if (data.expected_size != buf_size)
       continue;
-    EXPECT_EQ(0, memcmp(data.expected, buf, data.expected_size))
+    EXPECT_EQ(0, memcmp(data.expected, buf.get(), data.expected_size))
         << " for case " << i;
-    FX_Free(buf);
   }
 }