bk commit into 5.0 tree (gkodinov:1.2546) BUG#30715

[kgeorge]

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5.0 repository of kgeorge. When kgeorge does a push these changes will
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ChangeSet@stripped, 2007-10-18 14:40:17+03:00, gkodinov@stripped +3 -0
  Bug #30715: Assertion failed: item_field->field->real_maybe_null(), 
    file .\opt_sum.cc, line
  The MIN(field) can return NULL when all the row values in the group
  are NULL-able or if there were no rows.
  Fixed the assertion to reflect the case when there are no rows.

  mysql-test/r/func_group.result@stripped, 2007-10-18 14:40:15+03:00, gkodinov@stripped +4 -0
    Bug #30715: test case

  mysql-test/t/func_group.test@stripped, 2007-10-18 14:40:15+03:00, gkodinov@stripped +8 -0
    Bug #30715: test case

  sql/opt_sum.cc@stripped, 2007-10-18 14:40:15+03:00, gkodinov@stripped +2 -1
    Bug #30715: the field can be NULL if no rows
     were found when searching for the next group.

diff -Nrup a/mysql-test/r/func_group.result b/mysql-test/r/func_group.result
--- a/mysql-test/r/func_group.result	2007-10-08 12:57:41 +03:00
+++ b/mysql-test/r/func_group.result	2007-10-18 14:40:15 +03:00
@@ -1387,4 +1387,8 @@ SELECT 1 FROM t1 GROUP BY (SELECT SLEEP(
 1
 1
 DROP TABLE t1;
+CREATE TABLE t1 (a int, b date NOT NULL, KEY k1 (a,b));
+SELECT MIN(b) FROM t1 WHERE a=1 AND b>'2007-08-01';
+MIN(b)
+NULL
 End of 5.0 tests
diff -Nrup a/mysql-test/t/func_group.test b/mysql-test/t/func_group.test
--- a/mysql-test/t/func_group.test	2007-10-08 12:57:41 +03:00
+++ b/mysql-test/t/func_group.test	2007-10-18 14:40:15 +03:00
@@ -873,5 +873,13 @@ SELECT 1 FROM t1 GROUP BY (SELECT SLEEP(
 
 DROP TABLE t1;
 
+#
+# Bug #30715: Assertion failed: item_field->field->real_maybe_null(), file
+# .\opt_sum.cc, line
+#
+
+CREATE TABLE t1 (a int, b date NOT NULL, KEY k1 (a,b));
+SELECT MIN(b) FROM t1 WHERE a=1 AND b>'2007-08-01';
+
 ###
 --echo End of 5.0 tests
diff -Nrup a/sql/opt_sum.cc b/sql/opt_sum.cc
--- a/sql/opt_sum.cc	2007-05-15 15:29:10 +03:00
+++ b/sql/opt_sum.cc	2007-10-18 14:40:15 +03:00
@@ -260,7 +260,8 @@ int opt_sum_query(TABLE_LIST *tables, Li
                   (error == HA_ERR_KEY_NOT_FOUND ||
                    key_cmp_if_same(table, ref.key_buff, ref.key, prefix_len)))
               {
-                DBUG_ASSERT(item_field->field->real_maybe_null());
+                DBUG_ASSERT(error == HA_ERR_KEY_NOT_FOUND ||
+                            item_field->field->real_maybe_null());
                 error= table->file->index_read(table->record[0], ref.key_buff,
                                                ref.key_length, 
                                                HA_READ_KEY_EXACT);