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

[<gshchepa]

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ChangeSet@stripped, 2007-06-09 03:36:32+05:00, gshchepa@stripped +3 -0
  Fixed bug #28625:
  DECIMAL column was used instead of BIGINT for the minimal possible
  BIGINT (-9223372036854775808).
  
  The Item_func_neg::fix_length_and_dec has been adjusted to not set
  hybrid_type to DECIMAL_RESULT for abs(LONGLONG_MIN) argument value.

  mysql-test/r/bigint.result@stripped, 2007-06-09 03:35:36+05:00, gshchepa@stripped +7 -0
    Added test case for bug #28625.

  mysql-test/t/bigint.test@stripped, 2007-06-09 03:35:34+05:00, gshchepa@stripped +8 -0
    Added test result for bug #28625.

  sql/item_func.cc@stripped, 2007-06-09 03:36:05+05:00, gshchepa@stripped +7 -1
    Fixed bug #28625.
    The Item_func_neg::fix_length_and_dec has been adjusted to not set
    hybrid_type to DECIMAL_RESULT for abs(LONGLONG_MIN) argument value.

# 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 03:36:05 +05:00
@@ -1522,10 +1522,16 @@ void Item_func_neg::fix_length_and_dec()
     (This is how multiplication and other integer functions works)
     Use val() to get value as arg_type doesn't mean that item is
     Item_int or Item_real due to existence of Item_param.
+
+    NOTE: below we use the fact of "two's complement" representation of
+    signed numbers: -(longlong)LONGLONG_MIN == (longlong) LONGLONG_MIN.
+    So, it is ok to use INT_RESULT for Item_uint with value of
+    (ulonglong) LONGLONG_MIN: applying Item_func_neg::int_op to that value
+    we'll obtain correct result: (longlong) LONGLONG_MIN.
   */
   if (hybrid_type == INT_RESULT &&
       args[0]->type() == INT_ITEM &&
-      ((ulonglong) args[0]->val_int() >= (ulonglong) LONGLONG_MIN))
+      ((ulonglong) args[0]->val_int() > (ulonglong) LONGLONG_MIN))
   {
     /*
       Ensure that result is converted to DECIMAL, as longlong can't hold

--- 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 03:35:36 +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 03:35:34 +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;