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, 4 insertions, 25 deletions

diff --git a/src/liblzma/simple/simple_coder.c b/src/liblzma/simple/simple_coder.c
index f60dff34..6ecd119e 100644
--- a/src/liblzma/simple/simple_coder.c
+++ b/src/liblzma/simple/simple_coder.c
@@ -39,44 +39,23 @@ copy_or_code(lzma_coder *coder, lzma_allocator *allocator,
 	if (coder->next.code == NULL) {
 		const size_t in_avail = in_size - *in_pos;
 
-		if (coder->is_encoder) {
-			if (action == LZMA_FINISH) {
-				// If uncompressed size is known and the
-				// amount of available input doesn't match
-				// the uncompressed size, return an error.
-				if (coder->uncompressed_size
-						!= LZMA_VLI_VALUE_UNKNOWN
-						&& coder->uncompressed_size
-							!= in_avail)
-					return LZMA_DATA_ERROR;
-
-			} else if (coder->uncompressed_size
-					< (lzma_vli)(in_avail)) {
-				// There is too much input available.
-				return LZMA_DATA_ERROR;
-			}
-		} else {
+		if (!coder->is_encoder) {
 			// Limit in_size so that we don't copy too much.
 			if ((lzma_vli)(in_avail) > coder->uncompressed_size)
 				in_size = *in_pos + (size_t)(
 						coder->uncompressed_size);
 		}
 
-		// Store the old position so we can update uncompressed_size.
 		const size_t out_start = *out_pos;
-
-		// Copy the data
 		bufcpy(in, in_pos, in_size, out, out_pos, out_size);
 
-		// Update uncompressed_size.
-		if (coder->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN)
-			coder->uncompressed_size -= *out_pos - out_start;
-
 		// Check if end of stream was reached.
 		if (coder->is_encoder) {
 			if (action == LZMA_FINISH && *in_pos == in_size)
 				coder->end_was_reached = true;
-		} else {
+		} else if (coder->uncompressed_size
+				!= LZMA_VLI_VALUE_UNKNOWN) {
+			coder->uncompressed_size -= *out_pos - out_start;
 			if (coder->uncompressed_size == 0)
 				coder->end_was_reached = true;
 		}