Shrink Clean Table Area When Copying Table Contents into Context

The source matchState is potentially at a lower current index, which means
that any extra table space not overwritten by the copy may now contain
invalid indices. The simple solution is to unconditionally shrink the valid
table area to just the area overwritten.

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 3fb77d59a0e0a219118ca70b16fb6e0d3fd5950c..64fe952adce63dcd7a276e6b7e1092ac2318f2d8 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -1643,6 +1643,8 @@ static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
         assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
     }
 
+    ZSTD_cwksp_mark_tables_dirty(&cctx->workspace);
+
     /* copy tables */
     {   size_t const chainSize = (cdict_cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict_cParams->chainLog);
         size_t const hSize =  (size_t)1 << cdict_cParams->hashLog;
@@ -1660,6 +1662,8 @@ static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
         memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
     }
 
+    ZSTD_cwksp_mark_tables_clean(&cctx->workspace);
+
     /* copy dictionary offsets */
     {   ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
         ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
@@ -1728,6 +1732,8 @@ static size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx,
         assert(dstCCtx->blockState.matchState.hashLog3 == srcCCtx->blockState.matchState.hashLog3);
     }
 
+    ZSTD_cwksp_mark_tables_dirty(&dstCCtx->workspace);
+
     /* copy tables */
     {   size_t const chainSize = (srcCCtx->appliedParams.cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << srcCCtx->appliedParams.cParams.chainLog);
         size_t const hSize =  (size_t)1 << srcCCtx->appliedParams.cParams.hashLog;
@@ -1738,6 +1744,8 @@ static size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx,
         memcpy(dstCCtx->blockState.matchState.hashTable, srcCCtx->blockState.matchState.hashTable, tableSpace);   /* presumes all tables follow each other */
     }
 
+    ZSTD_cwksp_mark_tables_clean(&dstCCtx->workspace);
+
     /* copy dictionary offsets */
     {
         const ZSTD_matchState_t* srcMatchState = &srcCCtx->blockState.matchState;