diff --git a/include/my_global.h b/include/my_global.h
index 0d43964234b..695884cb6c6 100644
--- a/include/my_global.h
+++ b/include/my_global.h
@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1064,19 +1064,9 @@ typedef char		my_bool; /* Small bool */
 				  ((uint32) (uchar) (A)[0])))
 #define sint4korr(A)	(*((long *) (A)))
 #define uint2korr(A)	(*((uint16 *) (A)))
-#if defined(HAVE_purify) && !defined(_WIN32)
 #define uint3korr(A)	(uint32) (((uint32) ((uchar) (A)[0])) +\
 				  (((uint32) ((uchar) (A)[1])) << 8) +\
 				  (((uint32) ((uchar) (A)[2])) << 16))
-#else
-/*
-   ATTENTION !
-   
-    Please, note, uint3korr reads 4 bytes (not 3) !
-    It means, that you have to provide enough allocated space !
-*/
-#define uint3korr(A)	(long) (*((unsigned int *) (A)) & 0xFFFFFF)
-#endif /* HAVE_purify && !_WIN32 */
 #define uint4korr(A)	(*((uint32 *) (A)))
 #define uint5korr(A)	((ulonglong)(((uint32) ((uchar) (A)[0])) +\
 				    (((uint32) ((uchar) (A)[1])) << 8) +\
diff --git a/sql/net_serv.cc b/sql/net_serv.cc
index 9c0c84bb292..b2c36f7c29c 100644
--- a/sql/net_serv.cc
+++ b/sql/net_serv.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -179,12 +179,10 @@ my_bool net_realloc(NET *net, size_t length)
   pkt_length = (length+IO_SIZE-1) & ~(IO_SIZE-1); 
   /*
     We must allocate some extra bytes for the end 0 and to be able to
-    read big compressed blocks + 1 safety byte since uint3korr() in
-    my_real_read() may actually read 4 bytes depending on build flags and
-    platform.
+    read big compressed blocks in my_real_read().
   */
   if (!(buff= (uchar*) my_realloc((char*) net->buff, pkt_length +
-                                  NET_HEADER_SIZE + COMP_HEADER_SIZE + 1,
+                                  NET_HEADER_SIZE + COMP_HEADER_SIZE,
                                   MYF(MY_WME))))
   {
     /* @todo: 1 and 2 codes are identical. */
@@ -951,12 +949,11 @@ my_real_read(NET *net, size_t *complen)
 	if (net->compress)
 	{
           /*
-            The following uint3korr() may read 4 bytes, so make sure we don't
-            read unallocated or uninitialized memory. The right-hand expression
-            must match the size of the buffer allocated in net_realloc().
+            The right-hand expression must match the size of the buffer
+            allocated in net_realloc().
           */
           DBUG_ASSERT(net->where_b + NET_HEADER_SIZE + sizeof(uint32) <=
-                      net->max_packet + NET_HEADER_SIZE + COMP_HEADER_SIZE + 1);
+                      net->max_packet + NET_HEADER_SIZE + COMP_HEADER_SIZE);
 	  /*
 	    If the packet is compressed then complen > 0 and contains the
 	    number of bytes in the uncompressed packet
diff --git a/sql/records.cc b/sql/records.cc
index 7f74b84b2d7..ae7ec74c17d 100644
--- a/sql/records.cc
+++ b/sql/records.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -589,10 +589,9 @@ static int init_rr_cache(THD *thd, READ_RECORD *info)
   rec_cache_size= info->cache_records*info->reclength;
   info->rec_cache_size= info->cache_records*info->ref_length;
 
-  // We have to allocate one more byte to use uint3korr (see comments for it)
   if (info->cache_records <= 2 ||
       !(info->cache=(uchar*) my_malloc_lock(rec_cache_size+info->cache_records*
-					   info->struct_length+1,
+					   info->struct_length,
 					   MYF(0))))
     DBUG_RETURN(1);
 #ifdef HAVE_purify