1 files changed, 22 insertions, 13 deletions

diff --git a/src/liblzma/common/auto_decoder.c b/src/liblzma/common/auto_decoder.c
index bf355070..09acd6dc 100644
--- a/src/liblzma/common/auto_decoder.c
+++ b/src/liblzma/common/auto_decoder.c
@@ -14,7 +14,7 @@
 #include "alone_decoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	/// Stream decoder or LZMA_Alone decoder
 	lzma_next_coder next;
 
@@ -26,15 +26,17 @@ struct lzma_coder_s {
 		SEQ_CODE,
 		SEQ_FINISH,
 	} sequence;
-};
+} lzma_auto_coder;
 
 
 static lzma_ret
-auto_decode(lzma_coder *coder, const lzma_allocator *allocator,
+auto_decode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_auto_coder *coder = coder_ptr;
+
 	switch (coder->sequence) {
 	case SEQ_INIT:
 		if (*in_pos >= in_size)
@@ -100,8 +102,9 @@ auto_decode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-auto_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+auto_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_auto_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -109,8 +112,10 @@ auto_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_check
-auto_decoder_get_check(const lzma_coder *coder)
+auto_decoder_get_check(const void *coder_ptr)
 {
+	const lzma_auto_coder *coder = coder_ptr;
+
 	// It is LZMA_Alone if get_check is NULL.
 	return coder->next.get_check == NULL ? LZMA_CHECK_NONE
 			: coder->next.get_check(coder->next.coder);
@@ -118,9 +123,11 @@ auto_decoder_get_check(const lzma_coder *coder)
 
 
 static lzma_ret
-auto_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
+auto_decoder_memconfig(void *coder_ptr, uint64_t *memusage,
 		uint64_t *old_memlimit, uint64_t new_memlimit)
 {
+	lzma_auto_coder *coder = coder_ptr;
+
 	lzma_ret ret;
 
 	if (coder->next.memconfig != NULL) {
@@ -154,21 +161,23 @@ auto_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	if (flags & ~LZMA_SUPPORTED_FLAGS)
 		return LZMA_OPTIONS_ERROR;
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_auto_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_auto_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &auto_decode;
 		next->end = &auto_decoder_end;
 		next->get_check = &auto_decoder_get_check;
 		next->memconfig = &auto_decoder_memconfig;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
-	next->coder->memlimit = memlimit;
-	next->coder->flags = flags;
-	next->coder->sequence = SEQ_INIT;
+	coder->memlimit = memlimit;
+	coder->flags = flags;
+	coder->sequence = SEQ_INIT;
 
 	return LZMA_OK;
 }