liblzma: Make the use of lzma_allocator const-correct.

There is a tiny risk of causing breakage: If an application
assigns lzma_stream.allocator to a non-const pointer, such
code won't compile anymore. I don't know why anyone would do
such a thing though, so in practice this shouldn't cause trouble.

Thanks to Jan Kratochvil for the patch.

4 files changed, 21 insertions, 19 deletions

diff --git a/src/liblzma/lz/lz_decoder.c b/src/liblzma/lz/lz_decoder.c
index d74085cf..2328a8e7 100644
--- a/src/liblzma/lz/lz_decoder.c
+++ b/src/liblzma/lz/lz_decoder.c
@@ -126,7 +126,7 @@ decode_buffer(lzma_coder *coder,
 
 static lzma_ret
 lz_decode(lzma_coder *coder,
-		lzma_allocator *allocator lzma_attribute((__unused__)),
+		const lzma_allocator *allocator lzma_attribute((__unused__)),
 		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,
@@ -184,7 +184,7 @@ lz_decode(lzma_coder *coder,
 
 
 static void
-lz_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+lz_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 {
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder->dict.buf, allocator);
@@ -200,10 +200,10 @@ lz_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
 
 
 extern lzma_ret
-lzma_lz_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+lzma_lz_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters,
 		lzma_ret (*lz_init)(lzma_lz_decoder *lz,
-			lzma_allocator *allocator, const void *options,
+			const lzma_allocator *allocator, const void *options,
 			lzma_lz_options *lz_options))
 {
 	// Allocate the base structure if it isn't already allocated.
diff --git a/src/liblzma/lz/lz_decoder.h b/src/liblzma/lz/lz_decoder.h
index 7266e803..277900af 100644
--- a/src/liblzma/lz/lz_decoder.h
+++ b/src/liblzma/lz/lz_decoder.h
@@ -67,7 +67,7 @@ typedef struct {
 			lzma_vli uncompressed_size);
 
 	/// Free allocated resources
-	void (*end)(lzma_coder *coder, lzma_allocator *allocator);
+	void (*end)(lzma_coder *coder, const lzma_allocator *allocator);
 
 } lzma_lz_decoder;
 
@@ -83,9 +83,10 @@ typedef struct {
 
 
 extern lzma_ret lzma_lz_decoder_init(lzma_next_coder *next,
-		lzma_allocator *allocator, const lzma_filter_info *filters,
+		const lzma_allocator *allocator,
+		const lzma_filter_info *filters,
 		lzma_ret (*lz_init)(lzma_lz_decoder *lz,
-			lzma_allocator *allocator, const void *options,
+			const lzma_allocator *allocator, const void *options,
 			lzma_lz_options *lz_options));
 
 extern uint64_t lzma_lz_decoder_memusage(size_t dictionary_size);
diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c
index e2406965..1f9ecfd4 100644
--- a/src/liblzma/lz/lz_encoder.c
+++ b/src/liblzma/lz/lz_encoder.c
@@ -76,8 +76,9 @@ move_window(lzma_mf *mf)
 /// This function must not be called once it has returned LZMA_STREAM_END.
 ///
 static lzma_ret
-fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in,
-		size_t *in_pos, size_t in_size, lzma_action action)
+fill_window(lzma_coder *coder, const lzma_allocator *allocator,
+		const uint8_t *in, size_t *in_pos, size_t in_size,
+		lzma_action action)
 {
 	assert(coder->mf.read_pos <= coder->mf.write_pos);
 
@@ -148,7 +149,7 @@ fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in,
 
 
 static lzma_ret
-lz_encode(lzma_coder *coder, lzma_allocator *allocator,
+lz_encode(lzma_coder *coder, 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,
@@ -179,7 +180,7 @@ lz_encode(lzma_coder *coder, lzma_allocator *allocator,
 
 
 static bool
-lz_encoder_prepare(lzma_mf *mf, lzma_allocator *allocator,
+lz_encoder_prepare(lzma_mf *mf, const lzma_allocator *allocator,
 		const lzma_lz_options *lz_options)
 {
 	// For now, the dictionary size is limited to 1.5 GiB. This may grow
@@ -360,7 +361,7 @@ lz_encoder_prepare(lzma_mf *mf, lzma_allocator *allocator,
 
 
 static bool
-lz_encoder_init(lzma_mf *mf, lzma_allocator *allocator,
+lz_encoder_init(lzma_mf *mf, const lzma_allocator *allocator,
 		const lzma_lz_options *lz_options)
 {
 	// Allocate the history buffer.
@@ -461,7 +462,7 @@ lzma_lz_encoder_memusage(const lzma_lz_options *lz_options)
 
 
 static void
-lz_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
+lz_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 {
 	lzma_next_end(&coder->next, allocator);
 
@@ -479,7 +480,7 @@ lz_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
 
 
 static lzma_ret
-lz_encoder_update(lzma_coder *coder, lzma_allocator *allocator,
+lz_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
 		const lzma_filter *filters_null lzma_attribute((__unused__)),
 		const lzma_filter *reversed_filters)
 {
@@ -495,10 +496,10 @@ lz_encoder_update(lzma_coder *coder, lzma_allocator *allocator,
 
 
 extern lzma_ret
-lzma_lz_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters,
 		lzma_ret (*lz_init)(lzma_lz_encoder *lz,
-			lzma_allocator *allocator, const void *options,
+			const lzma_allocator *allocator, const void *options,
 			lzma_lz_options *lz_options))
 {
 #ifdef HAVE_SMALL
diff --git a/src/liblzma/lz/lz_encoder.h b/src/liblzma/lz/lz_encoder.h
index 741c4532..d11d4a95 100644
--- a/src/liblzma/lz/lz_encoder.h
+++ b/src/liblzma/lz/lz_encoder.h
@@ -199,7 +199,7 @@ typedef struct {
 			size_t *restrict out_pos, size_t out_size);
 
 	/// Free allocated resources
-	void (*end)(lzma_coder *coder, lzma_allocator *allocator);
+	void (*end)(lzma_coder *coder, const lzma_allocator *allocator);
 
 	/// Update the options in the middle of the encoding.
 	lzma_ret (*options_update)(lzma_coder *coder,
@@ -296,10 +296,10 @@ mf_read(lzma_mf *mf, uint8_t *out, size_t *out_pos, size_t out_size,
 
 
 extern lzma_ret lzma_lz_encoder_init(
-		lzma_next_coder *next, lzma_allocator *allocator,
+		lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters,
 		lzma_ret (*lz_init)(lzma_lz_encoder *lz,
-			lzma_allocator *allocator, const void *options,
+			const lzma_allocator *allocator, const void *options,
 			lzma_lz_options *lz_options));