This leaves one known alignment bug unfixed: If repeat count
doesn't fit into 28-bit integer, the encoder has to split
this to multiple Subblocks with Subblock Type `Repeating Data'.
The extra Subblocks may have wrong alignment. Correct alignment
is restored after the split Repeating Data has been completely
written out.
Since the encoder doesn't even try to fix the alignment unless
the size of Data is at least 4 bytes, to trigger this bug you
need at least 4 GiB of repeating data with sequence length of
4 or more bytes. Since the worst thing done by this bug is
misaligned data (no data corruption), this bug simply isn't
worth fixing, because a proper fix isn't simple.
The API for handing Subfilters was changed to make it
consistent with LZMA_SYNC_FLUSH.
A few sanity checks were added for Subfilter handling. Some
small bugs were fixed. More comments were added.
function is still shared between encoder and decoder, but the
actual coding is in separate files for encoder and decoder.
There are now separate functions for the actual delta
calculation depending on if Delta is the last filter in the
chain or not. If it is the last, the new code copies the
data from input to output buffer and does the delta
calculation at the same time. The old code first copied the
data, then did the delta in the target buffer, which required
reading through the data twice.
Support for LZMA_SYNC_FLUSH was added to the Delta encoder.
This doesn't change anything in the file format.
a forward port of b7b22fcb979a16d3a47c8001f058c9f7d4416068
from lzma-utils-legacy.git. I don't know if the new code base
builds on Windows, but this is a start.
too early if we hit End of Input while decoding a Subblock of
type Repeating Data. To keep the loop termination condition
elegant, the order of enumerations in coder->sequence were
changed.
To keep the case-labels in roughly the same order as the
enumerations in coder->sequence, large chunks of code was
moved around. This made the diff big and ugly compared to
the amount of the actual changes made.
in ia64_coder_init(). It triggered assert() in
simple_coder.c, and could have caused a buffer overflow.
This error was probably a copypaste mistake, since most
of the simple filters use unfiltered_max = 4.
table-based version from LZMA SDK 4.57. This should be
fast on most systems.
A simpler and smaller alternative version is also provided.
On some CPUs this can be even a little faster than the
default table-based version (see comments in fastpos.h),
but on most systems the table-based code is faster.
These changes implement support for LZMA_SYNC_FLUSH in LZMA
encoder, and move the temporary buffer needed by range encoder
from lzma_range_encoder structure to lzma_lz_encoder.
coder->lz.stream_end_was_reached. That variable
will be removed, and the check isn't required anyway.
Rearrange the check so that it doesn't make one to
think that there could be an integer overflow.
Lasse Collin