Make the memusage functions of LZMA1 and LZMA2 decoders

to validate the filter options.

src/liblzma/lzma/lzma2_decoder.c

@@ -261,11 +261,8 @@ lzma_lzma2_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
 extern uint64_t
 lzma_lzma2_decoder_memusage(const void *options)
 {
-	const uint64_t lzma_memusage = lzma_lzma_decoder_memusage(options);
-	if (lzma_memusage == UINT64_MAX)
-		return UINT64_MAX;
-
-	return sizeof(lzma_coder) + lzma_memusage;
+	return sizeof(lzma_coder)
+			+ lzma_lzma_decoder_memusage_nocheck(options);
 }
 
 

src/liblzma/lzma/lzma_decoder.c

@@ -1012,14 +1012,20 @@ lzma_lzma_lclppb_decode(lzma_options_lzma *options, uint8_t byte)
 
 
 extern uint64_t
-lzma_lzma_decoder_memusage(const void *options)
+lzma_lzma_decoder_memusage_nocheck(const void *options)
 {
 	const lzma_options_lzma *const opt = options;
-	const uint64_t lz_memusage = lzma_lz_decoder_memusage(opt->dict_size);
-	if (lz_memusage == UINT64_MAX)
+	return sizeof(lzma_coder) + lzma_lz_decoder_memusage(opt->dict_size);
+}
+
+
+extern uint64_t
+lzma_lzma_decoder_memusage(const void *options)
+{
+	if (!is_lclppb_valid(options))
 		return UINT64_MAX;
 
-	return sizeof(lzma_coder) + lz_memusage;
+	return lzma_lzma_decoder_memusage_nocheck(options);
 }
 
 

src/liblzma/lzma/lzma_decoder.h

@@ -49,6 +49,11 @@ extern bool lzma_lzma_lclppb_decode(
 extern lzma_ret lzma_lzma_decoder_create(
 		lzma_lz_decoder *lz, lzma_allocator *allocator,
 		const void *opt, size_t *dict_size);
+
+/// Gets memory usage without validating lc/lp/pb. This is used by LZMA2
+/// decoder, because raw LZMA2 decoding doesn't need lc/lp/pb.
+extern uint64_t lzma_lzma_decoder_memusage_nocheck(const void *options);
+
 #endif
 
 #endif