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Fix Dict Size Test in LZ4_compress_fast_continue()

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Dictionaries don't need to be > 4 bytes, they need to be >= 4 bytes. This test
was overly conservative.

Also removes the test in `LZ4_attach_dictionary()`.
This commit is contained in:
W. Felix Handte 2018-12-05 11:24:33 -08:00
parent 535636ff5c
commit 4e3accccb2
1 changed files with 2 additions and 4 deletions
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6
lib/lz4.c
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@ -1271,9 +1271,7 @@ void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dic
*/
LZ4_resetStream_fast(working_stream);
if (dictionary_stream != NULL
&& dictionary_stream->internal_donotuse.dictSize - 1 >= 4
/* intentional underflow */) {
if (dictionary_stream != NULL) {
/* If the current offset is zero, we will never look in the
* external dictionary context, since there is no value a table
* entry can take that indicate a miss. In that case, we need
@ -1321,7 +1319,7 @@ int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, const char* source, ch
if (acceleration < 1) acceleration = ACCELERATION_DEFAULT;
/* invalidate tiny dictionaries */
if ( (streamPtr->dictSize-1 < 4) /* intentional underflow */
if ( (streamPtr->dictSize-1 < 4-1) /* intentional underflow */
&& (dictEnd != (const BYTE*)source) ) {
DEBUGLOG(5, "LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small", streamPtr->dictSize, streamPtr->dictionary);
streamPtr->dictSize = 0;