Update XZ Utils to 5.0.3 (in deps)

src/liblzma/common/block_encoder.c

 ///////////////////////////////////////////////////////////////////////////////
 //
 /// \file       block_encoder.c
 /// \brief      Encodes .xz Blocks
 //
 //  Author:     Lasse Collin
 //
 //  This file has been put into the public domain.
 //  You can do whatever you want with this file.
 //
@@ skipping 126 matching lines @@
 block_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
 {
         lzma_next_end(&coder->next, allocator);
         lzma_free(coder, allocator);
         return;
 }
 
 
 static lzma_ret
 block_encoder_update(lzma_coder *coder, lzma_allocator *allocator,
-                const lzma_filter *filters lzma_attribute((unused)),
+                const lzma_filter *filters lzma_attribute((__unused__)),
                 const lzma_filter *reversed_filters)
 {
         if (coder->sequence != SEQ_CODE)
                 return LZMA_PROG_ERROR;
 
         return lzma_next_filter_update(
                         &coder->next, allocator, reversed_filters);
 }
 
 
 extern lzma_ret
 lzma_block_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
                 lzma_block *block)
 {
         lzma_next_coder_init(&lzma_block_encoder_init, next, allocator);
 
+        if (block == NULL)
+                return LZMA_PROG_ERROR;
+
+        // The contents of the structure may depend on the version so
+        // check the version first.
         if (block->version != 0)
                 return LZMA_OPTIONS_ERROR;
 
         // If the Check ID is not supported, we cannot calculate the check and
         // thus not create a proper Block.
         if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX)
                 return LZMA_PROG_ERROR;
 
         if (!lzma_check_is_supported(block->check))
                 return LZMA_UNSUPPORTED_CHECK;
@@ skipping 29 matching lines @@
 extern LZMA_API(lzma_ret)
 lzma_block_encoder(lzma_stream *strm, lzma_block *block)
 {
         lzma_next_strm_init(lzma_block_encoder_init, strm, block);
 
         strm->internal->supported_actions[LZMA_RUN] = true;
         strm->internal->supported_actions[LZMA_FINISH] = true;
 
         return LZMA_OK;
 }