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Disallow Too-Long Repcodes When Using an Attached Dict

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This commit is contained in:
W. Felix Handte 2018-05-23 12:51:09 -04:00
parent b97ad3f457
commit 2bfe43267e
1 changed files with 10 additions and 4 deletions
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14
lib/compress/zstd_double_fast.c
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@ -85,17 +85,23 @@ size_t ZSTD_compressBlock_doubleFast_generic(
const U32 dictIndexDelta = dictMode == ZSTD_dictMatchState ?
prefixLowestIndex - (U32)(dictEnd - dictBase) :
0;
const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
/* init */
ip += (dictMode == ZSTD_noDict && ip == prefixLowest);
{ U32 const maxRep = dictMode == ZSTD_dictMatchState ?
(U32)(ip - dictLowest) :
(U32)(ip - prefixLowest);
ip += (dictAndPrefixLength == 0);
if (dictMode == ZSTD_noDict) {
U32 const maxRep = (U32)(ip - prefixLowest);
if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
}
if (dictMode == ZSTD_dictMatchState) {
/* dictMatchState repCode checks don't currently handle repCode == 0
* disabling. */
assert(offset_1 <= dictAndPrefixLength);
assert(offset_2 <= dictAndPrefixLength);
}
/* Main Search Loop */
while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */