bzr commit into mysql-6.0-opt-subqueries branch (sergefp:2753)

[Sergey Petrunia]

#At file:///home/spetrunia/dev/mysql-6.0-merge/ based on revid:sergefp@stripped

 2753 Sergey Petrunia	2008-12-27 [merge]
      Merge
modified:
  mysql-test/r/func_math.result
  mysql-test/r/type_varchar.result
  mysql-test/t/func_math.test
  sql/item_func.cc

=== modified file 'mysql-test/r/func_math.result'
--- a/mysql-test/r/func_math.result	2008-11-24 09:53:39 +0000
+++ b/mysql-test/r/func_math.result	2008-12-22 12:44:57 +0000
@@ -383,8 +383,10 @@ SELECT b DIV 900 y FROM t1 GROUP BY y;
 y
 0
 Warnings:
-Warning	1292	Truncated incorrect INTEGER value: 'str1'
-Warning	1292	Truncated incorrect INTEGER value: 'str2'
+Warning	1366	Incorrect decimal value: '' for column '' at row -1
+Warning	1292	Truncated incorrect DECIMAL value: 'str1'
+Warning	1366	Incorrect decimal value: '' for column '' at row -1
+Warning	1292	Truncated incorrect DECIMAL value: 'str2'
 SELECT c DIV 900 y FROM t1 GROUP BY y;
 y
 0
@@ -460,3 +462,8 @@ SELECT POW(10, 309);
 POW(10, 309)
 NULL
 End of 5.1 tests
+select 123456789012345678901234567890.123456789012345678901234567890 div 1 as x;
+ERROR 22003: Out of range value for column 'x' at row 1
+select "123456789012345678901234567890.123456789012345678901234567890" div 1 as x;
+ERROR 22003: Out of range value for column 'x' at row 1
+End of 6.0 tests

=== modified file 'mysql-test/r/type_varchar.result'
--- a/mysql-test/r/type_varchar.result	2008-11-24 09:53:39 +0000
+++ b/mysql-test/r/type_varchar.result	2008-12-22 10:11:13 +0000
@@ -475,8 +475,9 @@ a	(a DIV 2)
 60	30
 t	0
 Warnings:
-Warning	1292	Truncated incorrect INTEGER value: '1a'
-Warning	1292	Truncated incorrect INTEGER value: 't '
+Warning	1292	Truncated incorrect DECIMAL value: '1a'
+Warning	1366	Incorrect decimal value: '' for column '' at row -1
+Warning	1292	Truncated incorrect DECIMAL value: 't '
 SELECT a,CAST(a AS SIGNED) FROM t1 ORDER BY a;
 a	CAST(a AS SIGNED)
 10	10

=== modified file 'mysql-test/t/func_math.test'
--- a/mysql-test/t/func_math.test	2008-04-07 15:57:54 +0000
+++ b/mysql-test/t/func_math.test	2008-12-11 15:27:05 +0000
@@ -283,3 +283,14 @@ SELECT EXP(750);
 SELECT POW(10, 309);
 
 --echo End of 5.1 tests
+
+#
+# Bug #8457: Precision math: DIV returns incorrect result with large decimal value
+#
+
+--error ER_WARN_DATA_OUT_OF_RANGE
+select 123456789012345678901234567890.123456789012345678901234567890 div 1 as x;
+--error ER_WARN_DATA_OUT_OF_RANGE
+select "123456789012345678901234567890.123456789012345678901234567890" div 1 as x; 
+
+--echo End of 6.0 tests

=== modified file 'sql/item_func.cc'
--- a/sql/item_func.cc	2008-12-14 11:36:15 +0000
+++ b/sql/item_func.cc	2008-12-24 10:22:24 +0000
@@ -1368,6 +1368,38 @@ void Item_func_div::fix_length_and_dec()
 longlong Item_func_int_div::val_int()
 {
   DBUG_ASSERT(fixed == 1);
+
+  /*
+    Perform division using DECIMAL math if either of the operands has a
+    non-integer type
+  */
+  if (args[0]->result_type() != INT_RESULT ||
+      args[1]->result_type() != INT_RESULT)
+  {
+    my_decimal value0, value1, tmp;
+    my_decimal *val0, *val1;
+    longlong res;
+    int err;
+
+    val0= args[0]->val_decimal(&value0);
+    val1= args[1]->val_decimal(&value1);
+    if ((null_value= (args[0]->null_value || args[1]->null_value)))
+      return 0;
+
+    if ((err= my_decimal_div(E_DEC_FATAL_ERROR & ~E_DEC_DIV_ZERO, &tmp,
+                             val0, val1, 0)) > 3)
+    {
+      if (err == E_DEC_DIV_ZERO)
+        signal_divide_by_null();
+      return 0;
+    }
+
+    if (my_decimal2int(E_DEC_FATAL_ERROR, &tmp, unsigned_flag, &res) &
+        E_DEC_OVERFLOW)
+      my_error(ER_WARN_DATA_OUT_OF_RANGE, MYF(0), name, 1);
+    return res;
+  }
+  
   longlong value=args[0]->val_int();
   longlong val2=args[1]->val_int();
   if ((null_value= (args[0]->null_value || args[1]->null_value)))