Don't create dict in streaming apis if dictSize == 0

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 4408644c6405f6c04e824d58495d3f971c0aca2f..df53db47028a1f00fb9f585f99467e4ecdcc6375 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2951,7 +2951,7 @@ size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
         if (zcs->outBuff == NULL) return ERROR(memory_allocation);
     }
 
-    if (dict) {
+    if (dict && dictSize >= 8) {
         ZSTD_freeCDict(zcs->cdictLocal);
         zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize, 0, params, zcs->customMem);
         if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);

diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index 30198f036acdd5cdf67e79e0ffd7b2bc3907481c..c53f3c3d17cca7bb46a3bbc03525ff1277874518 100644 (file)
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -1936,7 +1936,7 @@ size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t di
     zds->stage = zdss_loadHeader;
     zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
     ZSTD_freeDDict(zds->ddictLocal);
-    if (dict) {
+    if (dict && dictSize >= 8) {
         zds->ddictLocal = ZSTD_createDDict(dict, dictSize);
         if (zds->ddictLocal == NULL) return ERROR(memory_allocation);
     } else zds->ddictLocal = NULL;

diff --git a/lib/zstd.h b/lib/zstd.h
index 333feff7da1462a845fc7b7054d0aa6131c5ea80..52afc26bdd098d91303f83becdb1700de968202c 100644 (file)
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -510,7 +510,7 @@ ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
 /*=====   Advanced Streaming compression functions  =====*/
 ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
 ZSTDLIB_API size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize);   /**< pledgedSrcSize must be correct */
-ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel);
+ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); /* note: a dict will not be used if dict == NULL or dictSize < 8 */
 ZSTDLIB_API size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
                                              ZSTD_parameters params, unsigned long long pledgedSrcSize);  /**< pledgedSrcSize is optional and can be zero == unknown */
 ZSTDLIB_API size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);  /**< note : cdict will just be referenced, and must outlive compression session */
@@ -521,7 +521,7 @@ ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
 /*=====   Advanced Streaming decompression functions  =====*/
 typedef enum { ZSTDdsp_maxWindowSize } ZSTD_DStreamParameter_e;
 ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
-ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
+ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); /* note: a dict will not be used if dict == NULL or dictSize < 8 */
 ZSTDLIB_API size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);
 ZSTDLIB_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);  /**< note : ddict will just be referenced, and must outlive decompression session */
 ZSTDLIB_API size_t ZSTD_resetDStream(ZSTD_DStream* zds);  /**< re-use decompression parameters from previous init; saves dictionary loading */