1 files changed, 47 insertions, 52 deletions

diff --git a/src/liblzma/common/alone_encoder.c b/src/liblzma/common/alone_encoder.c
index 7629aa77..f94a21c1 100644
--- a/src/liblzma/common/alone_encoder.c
+++ b/src/liblzma/common/alone_encoder.c
@@ -21,19 +21,19 @@
 #include "lzma_encoder.h"
 
 
+#define ALONE_HEADER_SIZE (1 + 4 + 8)
+
+
 struct lzma_coder_s {
 	lzma_next_coder next;
 
 	enum {
-		SEQ_PROPERTIES,
-		SEQ_DICTIONARY_SIZE,
-		SEQ_UNCOMPRESSED_SIZE,
+		SEQ_HEADER,
 		SEQ_CODE,
 	} sequence;
 
-	size_t pos;
-
-	lzma_options_alone options;
+	size_t header_pos;
+	uint8_t header[ALONE_HEADER_SIZE];
 };
 
 
@@ -47,47 +47,23 @@ alone_encode(lzma_coder *coder,
 {
 	while (*out_pos < out_size)
 	switch (coder->sequence) {
-	case SEQ_PROPERTIES:
-		if (lzma_lzma_encode_properties(
-				&coder->options.lzma, out + *out_pos)) {
-			return LZMA_PROG_ERROR;
-		}
-
-		coder->sequence = SEQ_DICTIONARY_SIZE;
-		++*out_pos;
-		break;
-
-	case SEQ_DICTIONARY_SIZE:
-		out[*out_pos] = coder->options.lzma.dictionary_size
-				>> (coder->pos * 8);
-
-		if (++coder->pos == 4) {
-			coder->pos = 0;
-			coder->sequence = SEQ_UNCOMPRESSED_SIZE;
-		}
-
-		++*out_pos;
-		break;
-
-	case SEQ_UNCOMPRESSED_SIZE:
-		out[*out_pos] = coder->options.uncompressed_size
-				>> (coder->pos * 8);
-
-		if (++coder->pos == 8) {
-			coder->pos = 0;
-			coder->sequence = SEQ_CODE;
-		}
-
-		++*out_pos;
+	case SEQ_HEADER:
+		bufcpy(coder->header, &coder->header_pos,
+				ALONE_HEADER_SIZE,
+				out, out_pos, out_size);
+		if (coder->header_pos < ALONE_HEADER_SIZE)
+			return LZMA_OK;
+
+		coder->sequence = SEQ_CODE;
 		break;
 
-	case SEQ_CODE: {
+	case SEQ_CODE:
 		return coder->next.code(coder->next.coder,
 				allocator, in, in_pos, in_size,
 				out, out_pos, out_size, action);
-	}
 
 	default:
+		assert(0);
 		return LZMA_PROG_ERROR;
 	}
 
@@ -107,7 +83,7 @@ alone_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
 // At least for now, this is not used by any internal function.
 static lzma_ret
 alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
-		const lzma_options_alone *options)
+		const lzma_options_lzma *options)
 {
 	if (next->coder == NULL) {
 		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
@@ -119,23 +95,42 @@ alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
 		next->coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
-	// Initialize the LZMA_Alone coder variables.
-	next->coder->sequence = SEQ_PROPERTIES;
-	next->coder->pos = 0;
-	next->coder->options = *options;
+	// Basic initializations
+	next->coder->sequence = SEQ_HEADER;
+	next->coder->header_pos = 0;
 
-	// Verify uncompressed_size since the other functions assume that
-	// it is valid.
-	if (!lzma_vli_is_valid(next->coder->options.uncompressed_size))
+	// Encode the header:
+	// - Properties (1 byte)
+	if (lzma_lzma_encode_properties(options, next->coder->header))
 		return LZMA_PROG_ERROR;
 
+	// - Dictionary size (4 bytes)
+	if (options->dictionary_size < LZMA_DICTIONARY_SIZE_MIN
+			|| options->dictionary_size > LZMA_DICTIONARY_SIZE_MAX)
+		return LZMA_PROG_ERROR;
+
+	// Round up to to the next 2^n or 2^n + 2^(n - 1) depending on which
+	// one is the next. While the header would allow any 32-bit integer,
+	// we do this to keep the decoder of liblzma accepting the resulting
+	// files.
+	uint32_t d = options->dictionary_size - 1;
+	d |= d >> 2;
+	d |= d >> 3;
+	d |= d >> 4;
+	d |= d >> 8;
+	d |= d >> 16;
+	++d;
+
+	integer_write_32(next->coder->header + 1, d);
+
+	// - Uncompressed size (always unknown and using EOPM)
+	memset(next->coder->header + 1 + 4, 0xFF, 8);
+
 	// Initialize the LZMA encoder.
 	const lzma_filter_info filters[2] = {
 		{
 			.init = &lzma_lzma_encoder_init,
-			.options = &next->coder->options.lzma,
-			.uncompressed_size = next->coder->options
-					.uncompressed_size,
+			.options = (void *)(options),
 		}, {
 			.init = NULL,
 		}
@@ -156,7 +151,7 @@ lzma_alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
 
 
 extern LZMA_API lzma_ret
-lzma_alone_encoder(lzma_stream *strm, const lzma_options_alone *options)
+lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options)
 {
 	lzma_next_strm_init(strm, alone_encoder_init, options);