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| author | Alexey Kopytov <Alexey.Kopytov@Sun.com> | 2010-09-09 16:46:13 +0400 |
|---|---|---|
| committer | Alexey Kopytov <Alexey.Kopytov@Sun.com> | 2010-09-09 16:46:13 +0400 |
| commit | 453107bc561338e0764443561a11d05dbe6486ee (patch) | |
| tree | 233d8e7523dab779a2fc1a184a996a82ddd452fd /sql/item_cmpfunc.cc | |
| parent | 8822ecff2dea2e83fdad84d7a9307e8aa5905bce (diff) | |
| download | mariadb-git-453107bc561338e0764443561a11d05dbe6486ee.tar.gz | |
Bug #54190: Comparison to row subquery produces incorrect
result
Row subqueries producing no rows were not handled as UNKNOWN
values in row comparison expressions.
That was a result of the following two problems:
1. Item_singlerow_subselect did not mark the resulting row
value as NULL/UNKNOWN when no rows were produced.
2. Arg_comparator::compare_row() did not take into account that
a whole argument may be NULL rather than just individual scalar
values.
Before bug#34384 was fixed, the above problems were hidden
because an uninitialized (i.e. without any stored value) cached
object would appear as NULL for scalar values in a row subquery
returning an empty result. After the fix
Arg_comparator::compare_row() would try to evaluate
uninitialized cached objects.
Fixed by removing the aforementioned problems.
mysql-test/r/row.result:
Added a test case for bug #54190.
mysql-test/r/subselect.result:
Updated the result for a test relying on wrong behavior.
mysql-test/t/row.test:
Added a test case for bug #54190.
sql/item_cmpfunc.cc:
If either of the argument rows is NULL, return NULL as the
result of comparison.
sql/item_subselect.cc:
Adjust null_value for Item_singlerow_subselect depending on
whether a row has been produced by the row subquery.
Diffstat (limited to 'sql/item_cmpfunc.cc')
| -rw-r--r-- | sql/item_cmpfunc.cc | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc index fe4616f64d7..b2ed2df0f45 100644 --- a/sql/item_cmpfunc.cc +++ b/sql/item_cmpfunc.cc @@ -1583,6 +1583,13 @@ int Arg_comparator::compare_row() bool was_null= 0; (*a)->bring_value(); (*b)->bring_value(); + + if ((*a)->null_value || (*b)->null_value) + { + owner->null_value= 1; + return -1; + } + uint n= (*a)->cols(); for (uint i= 0; i<n; i++) { |