Remove uncompressed size tracking from the filter encoders.

It's not strictly needed there, and just complicates the
code. LZ encoder never even had this feature.

The primary reason to have uncompressed size tracking in
filter encoders was validating that the application
doesn't give different amount of input that it had
promised. A side effect was to validate internal workings
of liblzma.

Uncompressed size tracking is still present in the Block
encoder. Maybe it should be added to LZMA_Alone and raw
encoders too. It's simpler to have one coder just to
validate the uncompressed size instead of having it
in every filter.

1 files changed, 2 insertions, 23 deletions

diff --git a/src/liblzma/common/copy_coder.c b/src/liblzma/common/copy_coder.c
index 41f327d1..0bd674f6 100644
--- a/src/liblzma/common/copy_coder.c
+++ b/src/liblzma/common/copy_coder.c
@@ -42,33 +42,12 @@ copy_encode(lzma_coder *coder, lzma_allocator *allocator,
 				in, in_pos, in_size, out, out_pos, out_size,
 				action);
 
-	// If we get here, we are the last filter in the chain.
-	assert(coder->uncompressed_size <= LZMA_VLI_VALUE_MAX);
-
-	const size_t in_avail = in_size - *in_pos;
-
-	// Check that we don't have too much input.
-	if ((lzma_vli)(in_avail) > coder->uncompressed_size)
-		return LZMA_DATA_ERROR;
-
-	// Check that once LZMA_FINISH has been given, the amount of input
-	// matches uncompressed_size, which is always known.
-	if (action == LZMA_FINISH
-			&& coder->uncompressed_size != (lzma_vli)(in_avail))
-		return LZMA_DATA_ERROR;
-
 	// We are the last coder in the chain.
 	// Just copy as much data as possible.
-	const size_t in_used = bufcpy(
-			in, in_pos, in_size, out, out_pos, out_size);
-
-	// Update uncompressed_size if it is known.
-	if (coder->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN)
-		coder->uncompressed_size -= in_used;
+	bufcpy(in, in_pos, in_size, out, out_pos, out_size);
 
 	// LZMA_SYNC_FLUSH and LZMA_FINISH are the same thing for us.
-	if ((action != LZMA_RUN && *in_pos == in_size)
-			|| coder->uncompressed_size == 0)
+	if (action != LZMA_RUN && *in_pos == in_size)
 		return LZMA_STREAM_END;
 
 	return LZMA_OK;