diff -r 668eff08387f -r 675775c33ab6 contrib/python-zstandard/zstd/compress/hist.h
--- a/contrib/python-zstandard/zstd/compress/hist.h	Thu Apr 04 15:24:03 2019 -0700
+++ b/contrib/python-zstandard/zstd/compress/hist.h	Thu Apr 04 17:34:43 2019 -0700
@@ -41,11 +41,11 @@
 
 /*! HIST_count():
  *  Provides the precise count of each byte within a table 'count'.
- *  'count' is a table of unsigned int, of minimum size (*maxSymbolValuePtr+1).
+ * 'count' is a table of unsigned int, of minimum size (*maxSymbolValuePtr+1).
  *  Updates *maxSymbolValuePtr with actual largest symbol value detected.
- *  @return : count of the most frequent symbol (which isn't identified).
- *            or an error code, which can be tested using HIST_isError().
- *            note : if return == srcSize, there is only one symbol.
+ * @return : count of the most frequent symbol (which isn't identified).
+ *           or an error code, which can be tested using HIST_isError().
+ *           note : if return == srcSize, there is only one symbol.
  */
 size_t HIST_count(unsigned* count, unsigned* maxSymbolValuePtr,
                   const void* src, size_t srcSize);
@@ -56,14 +56,16 @@
 /* --- advanced histogram functions --- */
 
 #define HIST_WKSP_SIZE_U32 1024
+#define HIST_WKSP_SIZE    (HIST_WKSP_SIZE_U32 * sizeof(unsigned))
 /** HIST_count_wksp() :
  *  Same as HIST_count(), but using an externally provided scratch buffer.
  *  Benefit is this function will use very little stack space.
- * `workSpace` must be a table of unsigned of size >= HIST_WKSP_SIZE_U32
+ * `workSpace` is a writable buffer which must be 4-bytes aligned,
+ * `workSpaceSize` must be >= HIST_WKSP_SIZE
  */
 size_t HIST_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
                        const void* src, size_t srcSize,
-                       unsigned* workSpace);
+                       void* workSpace, size_t workSpaceSize);
 
 /** HIST_countFast() :
  *  same as HIST_count(), but blindly trusts that all byte values within src are <= *maxSymbolValuePtr.
@@ -74,11 +76,12 @@
 
 /** HIST_countFast_wksp() :
  *  Same as HIST_countFast(), but using an externally provided scratch buffer.
- * `workSpace` must be a table of unsigned of size >= HIST_WKSP_SIZE_U32
+ * `workSpace` is a writable buffer which must be 4-bytes aligned,
+ * `workSpaceSize` must be >= HIST_WKSP_SIZE
  */
 size_t HIST_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
                            const void* src, size_t srcSize,
-                           unsigned* workSpace);
+                           void* workSpace, size_t workSpaceSize);
 
 /*! HIST_count_simple() :
  *  Same as HIST_countFast(), this function is unsafe,