diff options
| -rw-r--r-- | src/liblzma/common/stream_encoder.c | 39 |
1 files changed, 31 insertions, 8 deletions
diff --git a/src/liblzma/common/stream_encoder.c b/src/liblzma/common/stream_encoder.c index 4dfe88cb..b15229c3 100644 --- a/src/liblzma/common/stream_encoder.c +++ b/src/liblzma/common/stream_encoder.c @@ -233,6 +233,13 @@ stream_encoder_update(void *coder_ptr, const lzma_allocator *allocator, const lzma_filter *reversed_filters) { lzma_stream_coder *coder = coder_ptr; + lzma_ret ret; + + // Make a copy to a temporary buffer first. This way it is easier + // to keep the encoder state unchanged if an error occurs with + // lzma_filters_copy(). + lzma_filter temp[LZMA_FILTERS_MAX + 1]; + return_if_error(lzma_filters_copy(filters, temp, allocator)); if (coder->sequence <= SEQ_BLOCK_INIT) { // There is no incomplete Block waiting to be finished, @@ -240,31 +247,47 @@ stream_encoder_update(void *coder_ptr, const lzma_allocator *allocator, // trying to initialize the Block encoder with the new // chain. This way we detect if the chain is valid. coder->block_encoder_is_initialized = false; - coder->block_options.filters = (lzma_filter *)(filters); - const lzma_ret ret = block_encoder_init(coder, allocator); + coder->block_options.filters = temp; + ret = block_encoder_init(coder, allocator); coder->block_options.filters = coder->filters; if (ret != LZMA_OK) - return ret; + goto error; coder->block_encoder_is_initialized = true; } else if (coder->sequence <= SEQ_BLOCK_ENCODE) { // We are in the middle of a Block. Try to update only // the filter-specific options. - return_if_error(coder->block_encoder.update( + ret = coder->block_encoder.update( coder->block_encoder.coder, allocator, - filters, reversed_filters)); + filters, reversed_filters); + if (ret != LZMA_OK) + goto error; } else { // Trying to update the filter chain when we are already // encoding Index or Stream Footer. - return LZMA_PROG_ERROR; + ret = LZMA_PROG_ERROR; + goto error; } - // Free the copy of the old chain and make a copy of the new chain. + // Free the options of the old chain. for (size_t i = 0; coder->filters[i].id != LZMA_VLI_UNKNOWN; ++i) lzma_free(coder->filters[i].options, allocator); - return lzma_filters_copy(filters, coder->filters, allocator); + // Copy the new filter chain in place. + size_t j = 0; + do { + coder->filters[j].id = temp[j].id; + coder->filters[j].options = temp[j].options; + } while (temp[j++].id != LZMA_VLI_UNKNOWN); + + return LZMA_OK; + +error: + for (size_t i = 0; temp[i].id != LZMA_VLI_UNKNOWN; ++i) + lzma_free(temp[i].options, allocator); + + return ret; } |