Change return value of GetAvailInput

This changes the return value from uint32_t to FX_FILESIZE, which is
the type the methods is uses return. The existing code does an
unguarded static cast, so something like -1 could cause a very large
value being returned.

This change has a cascading impact up to the top of the progressive
codec, which now has to handle negative values gracefully.

Change-Id: I813fb71e932dd5da014dbaed0dbf3bb28f8d4e9f
Reviewed-on: https://pdfium-review.googlesource.com/26450
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/core/fxcodec/codec/ccodec_bmpmodule.cpp b/core/fxcodec/codec/ccodec_bmpmodule.cpp
index e41b3dfd60..eb9bdf84f5 100644
--- a/core/fxcodec/codec/ccodec_bmpmodule.cpp
+++ b/core/fxcodec/codec/ccodec_bmpmodule.cpp
@@ -63,8 +63,8 @@ int32_t CCodec_BmpModule::LoadImage(Context* pContext) {
   return ctx->m_Bmp.DecodeImage();
 }
 
-uint32_t CCodec_BmpModule::GetAvailInput(Context* pContext,
-                                         uint8_t** avail_buf_ptr) {
+FX_FILESIZE CCodec_BmpModule::GetAvailInput(Context* pContext,
+                                            uint8_t** avail_buf_ptr) {
   auto* ctx = static_cast<CFX_BmpContext*>(pContext);
   return ctx->m_Bmp.GetAvailInput(avail_buf_ptr);
 }