bzr push into mysql-5.5 branch (tor.didriksen:3465 to 3466) Bug#12711164

[Tor Didriksen]

 3466 Tor Didriksen	2011-07-18
      Bug#12711164 - 61676: RESULT OF DIV WITH DECIMAL AND INTEGER DOES NOT MAKE SENSE 
      
      Truncate result of decimal division before converting to integer.
     @ mysql-test/r/func_math.result
        New test case.
     @ mysql-test/t/func_math.test
        New test case.
     @ sql/item_func.cc
        Item_func_int_div::val_int():
        Truncate result of decimal division before converting to integer.

    modified:
      mysql-test/r/func_math.result
      mysql-test/t/func_math.test
      sql/item_func.cc
 3465 Tor Didriksen	2011-07-18
      Bug#12537160 ASSERTION FAILED: STOP0 <= &TO->BUF[TO->LEN] WITH LARGE NUMBER.
      Turns out the DBUG_ASSERT added by fix for Bug#11792200 was overly pessimistic:
      'stop0' is used in the main loop of do_div_mod, but we only dereference 'buf0'
      for div operations, not for mod.
     @ mysql-test/r/func_math.result
        New test case.
     @ mysql-test/t/func_math.test
        New test case.
     @ strings/decimal.c
        Move DBUG_ASSERT down to where we actually dereference the loop pointer.

    modified:
      mysql-test/r/func_math.result
      mysql-test/t/func_math.test
      strings/decimal.c
=== modified file 'mysql-test/r/func_math.result'
--- a/mysql-test/r/func_math.result	2011-07-18 07:47:39 +0000
+++ b/mysql-test/r/func_math.result	2011-07-18 09:21:14 +0000
@@ -709,3 +709,22 @@ foo
 select 999999999999999999999999999999999999999999999999999999999999999999999999999999999 % 0.0 as foo;
 foo
 NULL
+#
+# Bug#12711164 - 61676:
+# RESULT OF DIV WITH DECIMAL AND INTEGER DOES NOT MAKE SENSE 
+#
+select 5 div 2;
+5 div 2
+2
+select 5.0 div 2.0;
+5.0 div 2.0
+2
+select 5.0 div 2;
+5.0 div 2
+2
+select 5 div 2.0;
+5 div 2.0
+2
+select 5.9 div 2, 1.23456789e3 DIV 2, 1.23456789e9 DIV 2, 1.23456789e19 DIV 2;
+5.9 div 2	1.23456789e3 DIV 2	1.23456789e9 DIV 2	1.23456789e19 DIV 2
[phone]	6172839450000000000

=== modified file 'mysql-test/t/func_math.test'
--- a/mysql-test/t/func_math.test	2011-07-18 07:47:39 +0000
+++ b/mysql-test/t/func_math.test	2011-07-18 09:21:14 +0000
@@ -547,3 +547,14 @@ let $nine_81=
 
 eval select $nine_81 % 0.1 as foo;
 eval select $nine_81 % 0.0 as foo;
+
+--echo #
+--echo # Bug#12711164 - 61676:
+--echo # RESULT OF DIV WITH DECIMAL AND INTEGER DOES NOT MAKE SENSE 
+--echo #
+
+select 5 div 2;
+select 5.0 div 2.0;
+select 5.0 div 2;
+select 5 div 2.0;
+select 5.9 div 2, 1.23456789e3 DIV 2, 1.23456789e9 DIV 2, 1.23456789e19 DIV 2;

=== modified file 'sql/item_func.cc'
--- a/sql/item_func.cc	2011-07-07 11:22:43 +0000
+++ b/sql/item_func.cc	2011-07-18 09:21:14 +0000
@@ -1605,8 +1605,13 @@ longlong Item_func_int_div::val_int()
       return 0;
     }
 
+    my_decimal truncated;
+    const bool do_truncate= true;
+    if (my_decimal_round(E_DEC_FATAL_ERROR, &tmp, 0, do_truncate, &truncated))
+      DBUG_ASSERT(false);
+
     longlong res;
-    if (my_decimal2int(E_DEC_FATAL_ERROR, &tmp, unsigned_flag, &res) &
+    if (my_decimal2int(E_DEC_FATAL_ERROR, &truncated, unsigned_flag, &res) &
         E_DEC_OVERFLOW)
       raise_integer_overflow();
     return res;

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