* libavi.c: improved parsing of some corrupted files.

modules/demux/avi/libavi.c

@@ -2,7 +2,7 @@
  * libavi.c :
  *****************************************************************************
  * Copyright (C) 2001 VideoLAN
- * $Id: libavi.c,v 1.9 2002/12/06 16:34:06 sam Exp $
+ * $Id: libavi.c,v 1.10 2002/12/16 13:04:36 fenrir Exp $
  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -270,7 +270,8 @@ static int AVI_ChunkReadCommon( input_thread_t *p_input,
     p_chk->common.p_next = NULL;
 #ifdef AVI_DEBUG
     msg_Dbg( p_input, 
-             "Found Chunk fourcc:%c%c%c%c size:"I64Fd" pos:"I64Fd,
+             "Found Chunk fourcc:%8.8x (%c%c%c%c) size:"I64Fd" pos:"I64Fd,
+             p_chk->common.i_chunk_fourcc,
              AVIFOURCC_PRINT( p_chk->common.i_chunk_fourcc ),
              p_chk->common.i_chunk_size,
              p_chk->common.i_chunk_pos );
@@ -356,12 +357,17 @@ static int AVI_ChunkRead_list( input_thread_t *p_input,
         }
     }
 
-    AVI_SkipBytes( p_input, 12 );
+    if( AVI_SkipBytes( p_input, 12 ) )
+    {
+        msg_Err( p_input, "cannot enter chunk" );
+        return VLC_EGENERIC;
+    }
 #ifdef AVI_DEBUG
     msg_Dbg( p_input, 
              "found LIST chunk: \'%c%c%c%c\'",
              AVIFOURCC_PRINT( p_container->list.i_type ) );
 #endif
+    msg_Dbg( p_input, "<list \'%c%c%c%c\'>", AVIFOURCC_PRINT( p_container->list.i_type ) );
     for( ; ; )
     {
         p_chk = malloc( sizeof( avi_chunk_t ) );
@@ -391,6 +397,7 @@ static int AVI_ChunkRead_list( input_thread_t *p_input,
         }
 
     }
+    msg_Dbg( p_input, "</list \'%c%c%c%c\'>", AVIFOURCC_PRINT( p_container->list.i_type ) );
 
     return VLC_SUCCESS;
 }
@@ -799,6 +806,11 @@ int  _AVI_ChunkRead( input_thread_t *p_input,
         msg_Warn( p_input, "cannot read one chunk" );
         return VLC_EGENERIC;
     }
+    if( p_chk->common.i_chunk_fourcc == VLC_FOURCC( 0, 0, 0, 0 ) )
+    {
+        msg_Warn( p_input, "found null fourcc chunk (corrupted file?)" );
+        return VLC_EGENERIC;
+    }
     p_chk->common.p_father = p_father;
 
     i_index = AVI_ChunkFunctionFind( p_chk->common.i_chunk_fourcc );