From 0605440f7344d9d6d1b047992fbadcd256f2c301 Mon Sep 17 00:00:00 2001

From: Frediano Ziglio <fziglio@redhat.com>

Date: Tue, 17 Jul 2018 16:24:06 +0100

Subject: [PATCH 4/4] jpeg: Do not use next_output_byte buf_empty_output_buffer

The pointer is not updated to the last byte used so using it

to compute the bytes written into the buffer we ignore some bytes

causing some image corruptions.

Note that also free_in_buffer is not updated to last written byte.

When buf_empty_output_buffer is called the buffer is full so use the

size of it instead of relying on next_output_byte or free_in_buffer.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>

Acked-by: Uri Lublin <uril@redhat.com>

---

 src/jpeg.cpp | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/jpeg.cpp b/src/jpeg.cpp

index ceee359..5f6d128 100644

--- a/src/jpeg.cpp

+++ b/src/jpeg.cpp

@@ -23,7 +23,7 @@ struct JpegBuffer: public jpeg_destination_mgr

 static boolean buf_empty_output_buffer(j_compress_ptr cinfo)

 {

     JpegBuffer *buf = (JpegBuffer *) cinfo->dest;

-    size_t size = buf->next_output_byte - &buf->buffer[0];

+    size_t size = buf->buffer.size();

     buf->buffer.resize(buf->buffer.capacity() * 2);

     buf->next_output_byte = &buf->buffer[0] + size;

     buf->free_in_buffer = buf->buffer.size() - size;

-- 

2.17.1