Fix a bug that JPX images can't be shown

core/src/fxcodec/codec/fx_codec_jpx_opj.cpp

 // Copyright 2014 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.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../../include/fxcodec/fx_codec.h"
 #include "codec_int.h"
 #include "../fx_libopenjpeg/libopenjpeg20/openjpeg.h"
 #include "../lcms2/include/fx_lcms2.h"
 static void fx_error_callback(const char *msg, void *client_data)
 {
     (void)client_data;
 }
 static void fx_warning_callback(const char *msg, void *client_data)
 {
     (void)client_data;
 }
 static void fx_info_callback(const char *msg, void *client_data)
 {
     (void)client_data;
 }
 struct DecodeData {

[Tom Sepez, 2015/03/16 17:51:20]

So if I'm making a unit test, this declaration moves to codec_int.h

     unsigned char* src_data;
     OPJ_SIZE_T     src_size;
     OPJ_SIZE_T     offset;
 };
 static OPJ_SIZE_T opj_read_from_memory (void * p_buffer, OPJ_SIZE_T p_nb_bytes,  void* p_user_data)

[Tom Sepez, 2015/03/16 17:51:20]

So if I'm making a unit test, these are not longer static functions, but
externals, and are prototpyed in codec_int.h

 {
     DecodeData* srcData = static_cast<DecodeData*>(p_user_data);
     if (srcData == NULL || srcData->src_size == 0 || srcData->src_data == NULL || srcData->offset >= srcData->src_size) {
         return -1;
     }
     OPJ_SIZE_T bufferLength = srcData->src_size - srcData->offset;
     OPJ_SIZE_T readlength = p_nb_bytes < bufferLength ? p_nb_bytes : bufferLength;
     memcpy(p_buffer, &srcData->src_data[srcData->offset], readlength);
     srcData->offset += readlength;
     return readlength;
 }
 static OPJ_SIZE_T opj_write_from_memory (void * p_buffer, OPJ_SIZE_T p_nb_bytes, void* p_user_data)
 {
     DecodeData* srcData = static_cast<DecodeData*>(p_user_data);
     if (srcData == NULL || srcData->src_size == 0 || srcData->src_data == NULL || srcData->offset >= srcData->src_size) {
         return -1;
     }
     OPJ_SIZE_T bufferLength = srcData->src_size - srcData->offset;
     OPJ_SIZE_T writeLength = p_nb_bytes < bufferLength ? p_nb_bytes : bufferLength;
     memcpy(&srcData->src_data[srcData->offset], p_buffer, writeLength);
     srcData->offset += writeLength;
     return writeLength;
 }
 static OPJ_OFF_T opj_skip_from_memory (OPJ_OFF_T p_nb_bytes, void* p_user_data)
 {
     DecodeData* srcData = static_cast<DecodeData*>(p_user_data);
-    if (srcData == NULL || srcData->src_size == 0 || srcData->src_data == NULL || srcData->offset >= srcData->src_size) {
+    if (srcData == NULL || srcData->src_size == 0 || srcData->src_data == NULL) {
         return -1;
     }
+    if (srcData->offset >= srcData->src_size) {
+        srcData->offset = srcData->src_size;
+        return p_nb_bytes;
+    }
     OPJ_SIZE_T bufferLength = srcData->src_size - srcData->offset;
     OPJ_SIZE_T skipLength = p_nb_bytes < bufferLength ? p_nb_bytes : bufferLength;
     srcData->offset += skipLength;
     return skipLength;
 }
 static OPJ_BOOL opj_seek_from_memory (OPJ_OFF_T p_nb_bytes, void* p_user_data)
 {
     DecodeData* srcData = static_cast<DecodeData*>(p_user_data);
-    if (srcData == NULL || srcData->src_size == 0 || srcData->src_data == NULL || srcData->offset >= srcData->src_size) {
+    if (srcData == NULL || srcData->src_size == 0 || srcData->src_data == NULL) {
         return OPJ_FALSE;
     }
+    if (srcData->offset >= srcData->src_size) {
+        return OPJ_TRUE;
+    }
     if (p_nb_bytes >= srcData->src_size) {
         return OPJ_FALSE;
     }
     srcData->offset = p_nb_bytes;
     return OPJ_TRUE;
 }
 opj_stream_t* fx_opj_stream_create_memory_stream (DecodeData* data,     OPJ_SIZE_T p_size,      OPJ_BOOL p_is_read_stream)
 {
     opj_stream_t* l_stream = 00;
     if (!data || ! data->src_data || data->src_size <= 0 ) {
@@ skipping 502 matching lines @@
     if (!src_data || src_size < sizeof(szJP2Header)) {
         return FALSE;
     }
     image = NULL;
     m_SrcData = src_data;
     m_SrcSize = src_size;
     DecodeData srcData;
     srcData.offset  = 0;
     srcData.src_size = src_size;
     srcData.src_data = const_cast<unsigned char*>(src_data);
     l_stream = fx_opj_stream_create_memory_stream(&srcData, OPJ_J2K_STREAM_CHUNK_SIZE, 1);

[Tom Sepez, 2015/03/16 17:24:52]

Doesn't srcData go out of scope and get destroyed while l_stream might still be
active?  Guess not based on line 649, but we can return with l_stream non-NULL
under error conditions?

     if (l_stream == NULL) {
         return FALSE;
     }
     opj_dparameters_t parameters;
     opj_set_default_decoder_parameters(&parameters);
     parameters.decod_format = 0;
     parameters.cod_format = 3;
     if(FXSYS_memcmp32(m_SrcData, szJP2Header, sizeof(szJP2Header)) == 0) {
         l_codec = opj_create_decompress(OPJ_CODEC_JP2);
         parameters.decod_format = 1;
@@ skipping 20 matching lines @@
         image->useColorSpace = 0;
     }
 */
     if (!parameters.nb_tile_to_decode) {
         if (!opj_set_decode_area(l_codec, image, parameters.DA_x0,
                                     parameters.DA_y0, parameters.DA_x1, parameters.DA_y1)) {
             opj_image_destroy(image);
             image = NULL;
             return FALSE;
         }
-        if (!(opj_decode(l_codec, l_stream, image) && opj_end_decompress(l_codec,       l_stream))) {
+        if (!(opj_decode(l_codec, l_stream, image) && opj_end_decompress(l_codec, l_stream))) {
             opj_image_destroy(image);
             image = NULL;
             return FALSE;
         }
     } else {
         if (!opj_get_decoded_tile(l_codec, l_stream, image, parameters.tile_index)) {
             return FALSE;
         }
     }
     opj_stream_destroy(l_stream);
     l_stream = NULL;
     if( image->color_space != OPJ_CLRSPC_SYCC
             && image->numcomps == 3 && image->comps[0].dx == image->comps[0].dy
             && image->comps[1].dx != 1 ) {
         image->color_space = OPJ_CLRSPC_SYCC;
     } else if (image->numcomps <= 2) {
         image->color_space = OPJ_CLRSPC_GRAY;
     }
     if(image->color_space == OPJ_CLRSPC_SYCC) {
         color_sycc_to_rgb(image);
     }
     //if(image->icc_profile_buf && !image->useColorSpace) {

[Tom Sepez, 2015/03/16 17:24:52]

nit: kill dead code while we're at it.

     if(image->icc_profile_buf) {
         FX_Free(image->icc_profile_buf);
         image->icc_profile_buf = NULL;
         image->icc_profile_len = 0;
     }
     if(!image) {
         return FALSE;
     }
     return TRUE;
 }
@@ skipping 120 matching lines @@
 FX_BOOL CCodec_JpxModule::Decode(void* ctx, FX_LPBYTE dest_data, int pitch, FX_BOOL bTranslateColor, FX_LPBYTE offsets)
 {
     CJPX_Decoder* pDecoder = (CJPX_Decoder*)ctx;
     return pDecoder->Decode(dest_data, pitch, bTranslateColor, offsets);
 }
 void CCodec_JpxModule::DestroyDecoder(void* ctx)
 {
     CJPX_Decoder* pDecoder = (CJPX_Decoder*)ctx;
     delete pDecoder;
 }