API : changed : streaming decompression : implicit reset on starting new frames

lib/decompress/zstd_decompress.c

@@ -1959,7 +1959,8 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
         switch(zds->stage)
         {
         case zdss_init :
-            return ERROR(init_missing);
+            ZSTD_resetDStream(zds);   /* transparent reset on starting decoding a new frame */
+            /* fall-through */
 
         case zdss_loadHeader :
             {   size_t const hSize = ZSTD_getFrameParams(&zds->fParams, zds->headerBuffer, zds->lhSize);

lib/zstd.h

@@ -299,8 +299,8 @@ ZSTDLIB_API size_t ZSTD_CStreamOutSize(void);   /**< recommended size for output
 *  If `output.pos < output.size`, decoder has flushed everything it could.
 *  @return : 0 when a frame is completely decoded and fully flushed,
 *            an error code, which can be tested using ZSTD_isError(),
-*            any other value > 0, which means there is still some work to do to complete the frame.
-*            The return value is a suggested next input size (just an hint, to help latency).
+*            any other value > 0, which means there is still some decoding to do to complete current frame.
+*            The return value is a suggested next input size (a hint to improve latency) that will never load more than the current frame.
 * *******************************************************************************/
 
 /*=====   Streaming decompression functions   =====*/