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Index decoder fixes.
The Index decoder code didn't perfectly match the API docs, which said that *i will be set to point to the decoded Index only after decoding has succeeded. The docs were a bit unclear too. Now the decoder will initially set *i to NULL. *i will be set to point to the decoded Index once decoding has succeeded. This simplifies applications too, since it avoids dangling pointers.
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465d1b0d65
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1f19690914
2 changed files with 32 additions and 17 deletions
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@ -317,12 +317,13 @@ extern LZMA_API(lzma_ret) lzma_index_encoder(lzma_stream *strm, lzma_index *i)
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* \brief Initialize .xz Index decoder
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* \brief Initialize .xz Index decoder
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*
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*
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* \param strm Pointer to properly prepared lzma_stream
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* \param strm Pointer to properly prepared lzma_stream
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* \param i Pointer to a pointer that will be made to point
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* \param i The decoded Index will be made available via
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* to the final decoded Index once lzma_code() has
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* this pointer. Initially this function will
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* returned LZMA_STREAM_END. That is,
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* set *i to NULL (the old value is ignored). If
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* lzma_index_decoder() always takes care of
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* decoding succeeds (lzma_code() returns
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* allocating a new lzma_index structure, and *i
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* LZMA_STREAM_END), *i will be set to point
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* doesn't need to be initialized by the caller.
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* to the decoded Index, which the application
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* has to later free with lzma_index_end().
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* \param memlimit How much memory the resulting Index is allowed
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* \param memlimit How much memory the resulting Index is allowed
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* to require.
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* to require.
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*
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*
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@ -373,11 +374,11 @@ extern LZMA_API(lzma_ret) lzma_index_buffer_encode(lzma_index *i,
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/**
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/**
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* \brief Single-call .xz Index decoder
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* \brief Single-call .xz Index decoder
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*
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*
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* \param i Pointer to a pointer that will be made to point
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* \param i If decoding succeeds, *i will point to the
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* to the final decoded Index if decoding is
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* decoded Index, which the application has to
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* successful. That is, lzma_index_buffer_decode()
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* later free with lzma_index_end(). If an error
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* always takes care of allocating a new
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* occurs, *i will be NULL. The old value of *i
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* lzma_index structure, and *i doesn't need to be
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* is always ignored and thus doesn't need to be
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* initialized by the caller.
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* initialized by the caller.
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* \param memlimit Pointer to how much memory the resulting Index
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* \param memlimit Pointer to how much memory the resulting Index
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* is allowed to require. The value pointed by
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* is allowed to require. The value pointed by
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@ -32,6 +32,10 @@ struct lzma_coder_s {
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/// Target Index
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/// Target Index
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lzma_index *index;
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lzma_index *index;
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/// Pointer give by the application, which is set after
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/// successful decoding.
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lzma_index **index_ptr;
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/// Number of Records left to decode.
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/// Number of Records left to decode.
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lzma_vli count;
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lzma_vli count;
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@ -174,6 +178,10 @@ index_decode(lzma_coder *coder, lzma_allocator *allocator,
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} while (++coder->pos < 4);
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} while (++coder->pos < 4);
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// Decoding was successful, now we can let the application
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// see the decoded Index.
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*coder->index_ptr = coder->index;
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// Make index NULL so we don't free it unintentionally.
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// Make index NULL so we don't free it unintentionally.
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coder->index = NULL;
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coder->index = NULL;
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@ -222,15 +230,21 @@ static lzma_ret
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index_decoder_reset(lzma_coder *coder, lzma_allocator *allocator,
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index_decoder_reset(lzma_coder *coder, lzma_allocator *allocator,
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lzma_index **i, uint64_t memlimit)
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lzma_index **i, uint64_t memlimit)
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{
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{
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// Remember the pointer given by the application. We will set it
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// to point to the decoded Index only if decoding is successful.
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// Before that, keep it NULL so that applications can always safely
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// pass it to lzma_index_end() no matter did decoding succeed or not.
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coder->index_ptr = i;
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*i = NULL;
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// We always allocate a new lzma_index.
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// We always allocate a new lzma_index.
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*i = lzma_index_init(NULL, allocator);
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coder->index = lzma_index_init(NULL, allocator);
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if (*i == NULL)
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if (coder->index == NULL)
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return LZMA_MEM_ERROR;
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return LZMA_MEM_ERROR;
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// Initialize the rest.
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// Initialize the rest.
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coder->sequence = SEQ_INDICATOR;
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coder->sequence = SEQ_INDICATOR;
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coder->memlimit = memlimit;
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coder->memlimit = memlimit;
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coder->index = *i;
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coder->count = 0; // Needs to be initialized due to _memconfig().
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coder->count = 0; // Needs to be initialized due to _memconfig().
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coder->pos = 0;
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coder->pos = 0;
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coder->crc32 = 0;
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coder->crc32 = 0;
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@ -282,7 +296,8 @@ lzma_index_buffer_decode(
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const uint8_t *in, size_t *in_pos, size_t in_size)
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const uint8_t *in, size_t *in_pos, size_t in_size)
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{
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{
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// Sanity checks
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// Sanity checks
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if (i == NULL || in == NULL || in_pos == NULL || *in_pos > in_size)
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if (i == NULL || memlimit == NULL
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|| in == NULL || in_pos == NULL || *in_pos > in_size)
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return LZMA_PROG_ERROR;
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return LZMA_PROG_ERROR;
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// Initialize the decoder.
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// Initialize the decoder.
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@ -302,8 +317,7 @@ lzma_index_buffer_decode(
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} else {
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} else {
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// Something went wrong, free the Index structure and restore
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// Something went wrong, free the Index structure and restore
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// the input position.
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// the input position.
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lzma_index_end(*i, allocator);
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lzma_index_end(coder.index, allocator);
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*i = NULL;
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*in_pos = in_start;
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*in_pos = in_start;
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if (ret == LZMA_OK) {
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if (ret == LZMA_OK) {
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