[vlc-devel] [PATCH] jpeg: add a comment and an assertion to explain error handling

[Rafaël Carré]

---
 modules/codec/jpeg.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/modules/codec/jpeg.c b/modules/codec/jpeg.c
index b03ca78..acc49aa 100644
--- a/modules/codec/jpeg.c
+++ b/modules/codec/jpeg.c
@@ -29,6 +29,7 @@
 #include <vlc_codec.h>
 #include <jpeglib.h>
 #include <setjmp.h>
+#include <assert.h>
 
 /*
  * jpeg decoder descriptor
@@ -140,6 +141,10 @@ static picture_t *DecodeBlock(decoder_t *p_dec, block_t **pp_block)
     }
 
     p_jpeg.err = jpeg_std_error(&p_sys->err);
+    /* XXX: we rely on p_sys->err being the first member of sys_t struct,
+    * so its address is the same than p_sys and we can retrieve p_sys
+    * address in libjpeg error handlers */
+    assert((decoder_sys_t*)p_sys->p_jpeg.err == p_sys);
     p_sys->err.error_exit = user_error_exit;
     p_sys->err.output_message = user_error_message;
 
-- 
1.8.5.3