Rename ErrorData and fix potential leakchromium/3100chromium/3099

This CL fixes a leak that can be caused by a longjmp in ErrorData. The method
is renamed to express the fact that it includes such, and a followup should
remove the jmps altogether.

Bug: chromium:721488
Change-Id: Iefcc82a77a30ff77b7973b05611440a8d5bf275e
Reviewed-on: https://pdfium-review.googlesource.com/5450
Commit-Queue: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

4 files changed, 24 insertions, 13 deletions

diff --git a/core/fxcodec/codec/fx_codec_progress.cpp b/core/fxcodec/codec/fx_codec_progress.cpp
index aa97ac4bb2..4cbae5cc75 100644
--- a/core/fxcodec/codec/fx_codec_progress.cpp
+++ b/core/fxcodec/codec/fx_codec_progress.cpp
@@ -1804,8 +1804,7 @@ FXCODEC_STATUS CCodec_ProgressiveDecoder::GetFrames(int32_t& frames) {
           m_status = FXCODEC_STATUS_DECODE_READY;
           return m_status;
         }
-        if (m_pGifContext.get())
-          m_pGifContext = nullptr;
+        m_pGifContext = nullptr;
         m_status = FXCODEC_STATUS_ERROR;
         return m_status;
       }
diff --git a/core/fxcodec/lgif/cgifcontext.cpp b/core/fxcodec/lgif/cgifcontext.cpp
index aa2aba6075..b7a513c7e8 100644
--- a/core/fxcodec/lgif/cgifcontext.cpp
+++ b/core/fxcodec/lgif/cgifcontext.cpp
@@ -33,7 +33,7 @@ CGifContext::CGifContext(CCodec_GifModule* gif_module, char* error_string)
 
 CGifContext::~CGifContext() {}
 
-void CGifContext::ErrorData(const char* err_msg) {
+void CGifContext::ThrowError(const char* err_msg) {
   strncpy(err_ptr, err_msg, GIF_MAX_ERROR_SIZE - 1);
   longjmp(jmpbuf, 1);
 }
diff --git a/core/fxcodec/lgif/cgifcontext.h b/core/fxcodec/lgif/cgifcontext.h
index 2ee8fbe396..e65d6c7b0b 100644
--- a/core/fxcodec/lgif/cgifcontext.h
+++ b/core/fxcodec/lgif/cgifcontext.h
@@ -21,7 +21,8 @@ class CGifContext {
   CGifContext(CCodec_GifModule* gif_module, char* error_string);
   ~CGifContext();
 
-  void ErrorData(const char* err_msg);
+  // TODO(npm): Remove longjmp from this method!!!
+  void ThrowError(const char* err_msg);
   void RecordCurrentPosition(uint32_t* cur_pos_ptr);
   void ReadScanline(int32_t row_num, uint8_t* row_buf);
   bool GetRecordPosition(uint32_t cur_pos,
diff --git a/core/fxcodec/lgif/fx_gif.cpp b/core/fxcodec/lgif/fx_gif.cpp
index b9ff41cc2e..dd80dc65f7 100644
--- a/core/fxcodec/lgif/fx_gif.cpp
+++ b/core/fxcodec/lgif/fx_gif.cpp
@@ -11,6 +11,7 @@
 
 #include "core/fxcodec/lbmp/fx_bmp.h"
 #include "core/fxcodec/lgif/cgifcontext.h"
+#include "third_party/base/logging.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/stl_util.h"
 
@@ -118,7 +119,8 @@ GifDecodeStatus gif_decode_extension(CGifContext* context) {
 
 GifDecodeStatus gif_decode_image_info(CGifContext* context) {
   if (context->width == 0 || context->height == 0) {
-    context->ErrorData("No Image Header Info");
+    context->ThrowError("No Image Header Info");
+    NOTREACHED();
     return GifDecodeStatus::Error;
   }
   uint32_t skip_size_org = context->skip_size;
@@ -141,7 +143,9 @@ GifDecodeStatus gif_decode_image_info(CGifContext* context) {
           context->width ||
       gif_image->m_ImageInfo.top + gif_image->m_ImageInfo.height >
           context->height) {
-    context->ErrorData("Image Data Out Of LSD, The File May Be Corrupt");
+    gif_image = nullptr;
+    context->ThrowError("Image Data Out Of LSD, The File May Be Corrupt");
+    NOTREACHED();
     return GifDecodeStatus::Error;
   }
   GifLF* gif_img_info_lf_ptr = (GifLF*)&gif_img_info_ptr->local_flag;
@@ -178,7 +182,8 @@ void gif_decoding_failure_at_tail_cleanup(CGifContext* context,
                                           GifImage* gif_image_ptr) {
   gif_image_ptr->m_ImageRowBuf.clear();
   gif_save_decoding_status(context, GIF_D_STATUS_TAIL);
-  context->ErrorData("Decode Image Data Error");
+  context->ThrowError("Decode Image Data Error");
+  NOTREACHED();
 }
 
 }  // namespace
@@ -361,7 +366,8 @@ GifDecodeStatus gif_read_header(CGifContext* context) {
 
   if (strncmp(gif_header_ptr->signature, GIF_SIGNATURE, 3) != 0 ||
       gif_header_ptr->version[0] != '8' || gif_header_ptr->version[2] != 'a') {
-    context->ErrorData("Not A Gif Image");
+    context->ThrowError("Not A Gif Image");
+    NOTREACHED();
     return GifDecodeStatus::Error;
   }
   GifLSD* gif_lsd_ptr = nullptr;
@@ -499,7 +505,8 @@ GifDecodeStatus gif_load_frame(CGifContext* context, int32_t frame_num) {
   GifImage* gif_image_ptr = context->m_Images[frame_num].get();
   uint32_t gif_img_row_bytes = gif_image_ptr->m_ImageInfo.width;
   if (gif_img_row_bytes == 0) {
-    context->ErrorData("Error Invalid Number of Row Bytes");
+    context->ThrowError("Error Invalid Number of Row Bytes");
+    NOTREACHED();
     return GifDecodeStatus::Error;
   }
   if (context->decode_status == GIF_D_STATUS_TAIL) {
@@ -522,7 +529,8 @@ GifDecodeStatus gif_load_frame(CGifContext* context, int32_t frame_num) {
           (bool)((GifLF*)&gif_image_ptr->m_ImageInfo.local_flag)->interlace);
       if (!bRes) {
         gif_image_ptr->m_ImageRowBuf.clear();
-        context->ErrorData("Error Read Record Position Data");
+        context->ThrowError("Error Read Record Position Data");
+        NOTREACHED();
         return GifDecodeStatus::Error;
       }
     } else {
@@ -540,13 +548,15 @@ GifDecodeStatus gif_load_frame(CGifContext* context, int32_t frame_num) {
           (bool)((GifLF*)&gif_image_ptr->m_ImageInfo.local_flag)->interlace);
       if (!bRes) {
         gif_image_ptr->m_ImageRowBuf.clear();
-        context->ErrorData("Error Read Record Position Data");
+        context->ThrowError("Error Read Record Position Data");
+        NOTREACHED();
         return GifDecodeStatus::Error;
       }
     }
     if (gif_image_ptr->image_code_size >= 32) {
       gif_image_ptr->m_ImageRowBuf.clear();
-      context->ErrorData("Error Invalid Code Size");
+      context->ThrowError("Error Invalid Code Size");
+      NOTREACHED();
       return GifDecodeStatus::Error;
     }
     if (!context->m_ImgDecoder.get())
@@ -643,7 +653,8 @@ GifDecodeStatus gif_load_frame(CGifContext* context, int32_t frame_num) {
     }
     gif_save_decoding_status(context, GIF_D_STATUS_TAIL);
   }
-  context->ErrorData("Decode Image Data Error");
+  context->ThrowError("Decode Image Data Error");
+  NOTREACHED();
   return GifDecodeStatus::Error;
 }