bk commit into 5.0 tree (ramil:1.2542) BUG#31349

[ramil]

Below is the list of changes that have just been committed into a local
5.0 repository of ram. When ram does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2007-10-19 14:54:05+05:00, ramil@stripped +3 -0
  Fix for bug #31349: ERROR 1062 (23000): Duplicate entry '' for key 'group_key'
  
  Problem: lying to the optimizer that a function (Item_func_inet_ntoa)
  cannot return NULL values leads to unexpected results (in the case group
  keys creation/comparison is broken). 
  
  Fix: Item_func_inet_ntoa::maybe_null should be set properly.

  mysql-test/r/func_misc.result@stripped, 2007-10-19 14:54:03+05:00, ramil@stripped +6 -0
    Fix for bug #31349: ERROR 1062 (23000): Duplicate entry '' for key 'group_key'
      - test result.

  mysql-test/t/func_misc.test@stripped, 2007-10-19 14:54:03+05:00, ramil@stripped +8 -0
    Fix for bug #31349: ERROR 1062 (23000): Duplicate entry '' for key 'group_key'
      - test case.

  sql/item_strfunc.h@stripped, 2007-10-19 14:54:03+05:00, ramil@stripped +6 -1
    Fix for bug #31349: ERROR 1062 (23000): Duplicate entry '' for key 'group_key'
      - set Item_func_inet_ntoa::maybe_null flag.

diff -Nrup a/mysql-test/r/func_misc.result b/mysql-test/r/func_misc.result
--- a/mysql-test/r/func_misc.result	2007-03-02 06:20:46 +04:00
+++ b/mysql-test/r/func_misc.result	2007-10-19 14:54:03 +05:00
@@ -185,4 +185,10 @@ ERROR 21000: Operand should contain 1 co
 drop table table_26093;
 drop function func_26093_a;
 drop function func_26093_b;
+create table t1 (a int not null);
+insert into t1 values (-1), (-2);
+select min(a) from t1 group by inet_ntoa(a);
+min(a)
+-2
+drop table t1;
 End of 5.0 tests
diff -Nrup a/mysql-test/t/func_misc.test b/mysql-test/t/func_misc.test
--- a/mysql-test/t/func_misc.test	2007-03-02 06:20:46 +04:00
+++ b/mysql-test/t/func_misc.test	2007-10-19 14:54:03 +05:00
@@ -189,4 +189,12 @@ drop table table_26093;
 drop function func_26093_a;
 drop function func_26093_b;
 
+#
+# Bug #31349: ERROR 1062 (23000): Duplicate entry '' for key 'group_key'
+#
+create table t1 (a int not null);
+insert into t1 values (-1), (-2);
+select min(a) from t1 group by inet_ntoa(a);
+drop table t1;
+
 --echo End of 5.0 tests
diff -Nrup a/sql/item_strfunc.h b/sql/item_strfunc.h
--- a/sql/item_strfunc.h	2007-07-27 18:42:24 +05:00
+++ b/sql/item_strfunc.h	2007-10-19 14:54:03 +05:00
@@ -683,7 +683,12 @@ public:
     }
   String* val_str(String* str);
   const char *func_name() const { return "inet_ntoa"; }
-  void fix_length_and_dec() { decimals = 0; max_length=3*8+7; }
+  void fix_length_and_dec() 
+  { 
+    decimals= 0; 
+    max_length= 3 * 8 + 7; 
+    maybe_null= 1;
+  }
 };
 
 class Item_func_quote :public Item_str_func