bk commit into 5.0 tree (gshchepa:1.2506) BUG#28625

[<gshchepa]

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ChangeSet@stripped, 2007-06-09 21:27:06+05:00, gshchepa@stripped +5 -0
  Fixed bug #28625:
  DECIMAL column was used instead of BIGINT for the minimal possible
  BIGINT (-9223372036854775808).
  
  Partial evaluation mechanism was added to Item_func_neg for
  the case of LONGLONG_MIN constant argment.

  mysql-test/r/bigint.result@stripped, 2007-06-09 21:18:51+05:00, gshchepa@stripped +7 -0
    Added test case for bug #28625.

  mysql-test/t/bigint.test@stripped, 2007-06-09 21:18:50+05:00, gshchepa@stripped +8 -0
    Added test result for bug #28625.

  sql/item_func.cc@stripped, 2007-06-09 21:18:53+05:00, gshchepa@stripped +79 -0
    Fixed bug #28625.
    The Item_func_neg::partial_eval method has been added to
    implement partial evaluation mechanism for case of LONGLONG_MIN
    argument.

  sql/item_func.h@stripped, 2007-06-09 21:24:16+05:00, gshchepa@stripped +1 -0
    Fixed bug #28625.
    The Item_func_neg::partial_eval method has been added.

  sql/sql_yacc.yy@stripped, 2007-06-09 21:24:30+05:00, gshchepa@stripped +1 -1
    Fixed bug #28625.
    The Item_func_neg::partial_eval method has been used
    instead of direct call to Item_func_neg class constructor.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	gshchepa
# Host:	gleb.loc
# Root:	/home/uchum/work/bk/5.0-opt-28625

--- 1.344/sql/item_func.cc	2007-06-01 02:17:03 +05:00
+++ 1.345/sql/item_func.cc	2007-06-09 21:18:53 +05:00
@@ -1475,6 +1475,85 @@ void Item_func_mod::fix_length_and_dec()
 }
 
 
+/*
+  Prepend given expression string with unary minus sign
+
+  SYNOPSIS
+    alloc_negated_string()
+    thd         Thread object
+    str         Pointer to original expression string
+    length      Length of str excluding terminating '\0' byte
+
+  DESCRIPTION
+    The alloc_negated_string function allocates new string and
+    fill it with unary minus sign and data of given expression
+    string `str' of size `length'. When it is necessary,
+    alloc_negated_string() also surrounds `str' with brackets.
+
+  RETURN
+    Allocated string with length.
+*/
+
+static LEX_STRING alloc_negated_string(THD *thd, const char *str, uint length)
+{
+  LEX_STRING tmp;
+  if (my_isdigit(thd->charset(), *str))
+  {
+    tmp.length= length + 1;                       // +1 for '-'
+    tmp.str= (char *) thd->alloc(tmp.length + 1); // +1 for '\0'
+    tmp.str[0]= '-';
+    memcpy(tmp.str + 1, str, length);
+  }
+  else
+  {
+    tmp.length= length + 3;                       // +3 for '-', '(' and ')'
+    tmp.str= (char *) thd->alloc(tmp.length + 1); // +1 for '\0'
+    tmp.str[0]= '-';
+    tmp.str[1]= '(';
+    memcpy(tmp.str + 2, str, length);
+    tmp.str[tmp.length - 1]= ')';
+  }
+  tmp.str[tmp.length]= '\0';
+  return tmp;
+}
+
+
+/*
+  Partially evaluate Item_func_neg when it is possible
+
+  SYNOPSIS
+    Item_func_neg::partial_eval()
+    thd         Thread object
+    a           Pointer to argument object
+
+  DESCRIPTION
+    The partial_eval method applies negation operator to
+    the given argument on the fly when it is possible and
+    returns Item_int object instead of Item_func_neg.
+
+  RETURN
+    Allocated Item object.
+
+  NOTE
+    Currently this method applies unary minus to Item_uint
+    constant of value (ulonglong) LONGLONG_MIN only.
+    TODO: improve the partial_eval method to deal with
+    another numeric constants.
+*/
+
+Item* Item_func_neg::partial_eval(THD *thd, Item *a)
+{
+  if (a->type() == INT_ITEM &&
+      a->unsigned_flag &&
+      a->val_int() == LONGLONG_MIN)
+  {
+    LEX_STRING tmp= alloc_negated_string(thd, a->name, a->max_length);
+    return new Item_int(tmp.str, LONGLONG_MIN, tmp.length);
+  }
+  return new Item_func_neg(a);
+}
+
+
 double Item_func_neg::real_op()
 {
   double value= args[0]->val_real();

--- 1.170/sql/item_func.h	2007-06-01 02:17:03 +05:00
+++ 1.171/sql/item_func.h	2007-06-09 21:24:16 +05:00
@@ -430,6 +430,7 @@ public:
 class Item_func_neg :public Item_func_num1
 {
 public:
+  static Item* partial_eval(THD *thd, Item *a);
   Item_func_neg(Item *a) :Item_func_num1(a) {}
   double real_op();
   longlong int_op();

--- 1.519/sql/sql_yacc.yy	2007-05-15 14:56:05 +05:00
+++ 1.520/sql/sql_yacc.yy	2007-06-09 21:24:30 +05:00
@@ -4673,7 +4673,7 @@ simple_expr:
 	| simple_expr OR_OR_SYM simple_expr
 	  { $$= new Item_func_concat($1, $3); }
 	| '+' simple_expr %prec NEG	{ $$= $2; }
-	| '-' simple_expr %prec NEG	{ $$= new Item_func_neg($2); }
+	| '-' simple_expr %prec NEG	{ $$= Item_func_neg::partial_eval(YYTHD, $2); }
 	| '~' simple_expr %prec NEG	{ $$= new Item_func_bit_neg($2); }
 	| not2 simple_expr %prec NEG	{ $$= negate_expression(YYTHD, $2); }
 	| '(' subselect ')'   

--- 1.35/mysql-test/r/bigint.result	2007-05-16 10:12:48 +05:00
+++ 1.36/mysql-test/r/bigint.result	2007-06-09 21:18:51 +05:00
@@ -362,3 +362,10 @@ cast(-19999999999999999999 as signed)
 -9223372036854775808
 Warnings:
 Error	1292	Truncated incorrect DECIMAL value: ''
+create table t1 select -9223372036854775808;
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `-9223372036854775808` bigint(20) NOT NULL default '0'
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop table t1;

--- 1.30/mysql-test/t/bigint.test	2007-05-16 10:12:48 +05:00
+++ 1.31/mysql-test/t/bigint.test	2007-06-09 21:18:50 +05:00
@@ -294,3 +294,11 @@ drop table t1;
 
 select cast(19999999999999999999 as signed);
 select cast(-19999999999999999999 as signed);
+
+#
+# Bug #28625: -9223372036854775808 doesn't fit in BIGINT.
+#
+
+create table t1 select -9223372036854775808;
+show create table t1;
+drop table t1;