From: Bimba Shrestha <bimbashrestha@fb.com>
Date: Fri, 20 Sep 2019 22:50:58 +0000 (-0700)
Subject: Passing in dummy dst buffer of compressbound(srcSize)
X-Git-Tag: v1.4.4~1^2~38^2~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f3c4fd17e30465a4ec90152c9f858dc8ff674b7f;p=thirdparty%2Fzstd.git

Passing in dummy dst buffer of compressbound(srcSize)
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index ce352acde..e7ec1d61f 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2319,6 +2319,9 @@ static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
 size_t ZSTD_getSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
     size_t outSeqsSize, const void* src, size_t srcSize)
 {
+    const size_t dstCapacity = ZSTD_compressBound(srcSize);
+    void* dst = ZSTD_malloc(dstCapacity, ZSTD_defaultCMem);
+
     SeqCollector seqCollector;
     seqCollector.collectSequences = 1;
     seqCollector.seqStart = outSeqs;
@@ -2326,8 +2329,8 @@ size_t ZSTD_getSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
     seqCollector.maxSequences = outSeqsSize;
     zc->seqCollector = seqCollector;
 
-    /* We never write to dst when collecing sequences so setting dst = src is harmless */
-    ZSTD_compress2(zc, (void*)src, srcSize, src, srcSize);
+    ZSTD_compress2(zc, dst, dstCapacity, src, srcSize);
+    ZSTD_free(dst, ZSTD_defaultCMem);
     return zc->seqCollector.seqIndex;
 }