Merge with MariaDB 5.1

1 files changed, 38 insertions, 8 deletions

diff --git a/sql/my_decimal.h b/sql/my_decimal.h
index 86f5db29ed7..845aecb972c 100644
--- a/sql/my_decimal.h
+++ b/sql/my_decimal.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2006 MySQL AB
+/*
+   Copyright (c) 2005, 2010, Oracle and/or its affiliates.
 
    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
@@ -11,7 +12,8 @@
 
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+*/
 
 /**
   @file
@@ -55,7 +57,7 @@ C_MODE_END
 
 /**
   maximum length of string representation (number of maximum decimal
-  digits + 1 position for sign + 1 position for decimal point)
+  digits + 1 position for sign + 1 position for decimal point, no terminator)
 */
 #define DECIMAL_MAX_STR_LENGTH (DECIMAL_MAX_POSSIBLE_PRECISION + 2)
 
@@ -91,24 +93,51 @@ inline int my_decimal_int_part(uint precision, uint decimals)
 
 class my_decimal :public decimal_t
 {
+  /*
+    Several of the routines in strings/decimal.c have had buffer
+    overrun/underrun problems. These are *not* caught by valgrind.
+    To catch them, we allocate dummy fields around the buffer,
+    and test that their values do not change.
+   */
+#if !defined(DBUG_OFF)
+  int foo1;
+#endif
+
   decimal_digit_t buffer[DECIMAL_BUFF_LENGTH];
 
+#if !defined(DBUG_OFF)
+  int foo2;
+  static const int test_value= 123;
+#endif
+
 public:
 
   void init()
   {
+#if !defined(DBUG_OFF)
+    foo1= test_value;
+    foo2= test_value;
+#endif
     len= DECIMAL_BUFF_LENGTH;
     buf= buffer;
-#if !defined (HAVE_valgrind) && !defined(DBUG_OFF)
-    /* Set buffer to 'random' value to find wrong buffer usage */
-    for (uint i= 0; i < DECIMAL_BUFF_LENGTH; i++)
-      buffer[i]= i;
-#endif
+    TRASH(buffer, sizeof(buffer));
   }
+
   my_decimal()
   {
     init();
   }
+  ~my_decimal()
+  {
+    sanity_check();
+  }
+
+  void sanity_check()
+  {
+    DBUG_ASSERT(foo1 == test_value);
+    DBUG_ASSERT(foo2 == test_value);
+  }
+
   void fix_buffer_pointer() { buf= buffer; }
 
   bool sign() const { return decimal_t::sign; }
@@ -212,6 +241,7 @@ inline uint32 my_decimal_precision_to_length(uint precision, uint8 scale,
 inline
 int my_decimal_string_length(const my_decimal *d)
 {
+  /* length of string representation including terminating '\0' */
   return decimal_string_size(d);
 }