Absence of table in left part of LEFT/RIGHT join wasn't checked before
name resolution which resulted in NULL dereferencing and server crash.
Modified rules:
"table_ref LEFT opt_outer JOIN_SYM table_ref" and "table_ref RIGHT opt_outer
JOIN_SYM table_ref"
NULL check is moved before push_new_name_resolution_context()
functions are involved.
When subselect is a join with set functions and no record have been found in
it, end_send_group() sets null_row for all tables in order aggregate functions
to calculate their values correctly. Normally this null_row flag is cleared for
each table in sub_select(), but flush_cached_records() doesn't do so.
Due to this all fields from the table processed by flush_cached_records() are
always evaluated as nulls and whole select produces wrong result.
flush_cached_records() now clears null_row flag at the very beginning.
select result
Item equal objects are employed only at the optimize phase. Usually they are not
supposed to be evaluated. Yet in some cases we call the method val_int() for
them. Here we have to take care of restricting the predicate such an object
represents f1=f2= ...=fn to the projection of known fields fi1=...=fik.
Added a check for field's table being const in Item_equal::val_int().
If the field's table is not const val_int() just skips that field when
evaluating Item_equal.
cmp_item_sort_string::cmp() wasn't checking values_res variable for null.
Later called function was dereferenced it and crashed server.
Added null check to cmp_item_sort_string::cmp().
crash
resolve_const_item() substitutes item which will evaluate to constant with
equvalent constant item, basing on the item's result type. In this case
subselect was resolved as constant, and resolve_const_item() was substituting
it's result's Item_caches to Item_null. Later Item_cache's function was called
for Item_null object, which caused server crash.
resolve_const_item() now substitutes constants for items with
result_type == ROW_RESULT only for Item_rows.
the same column as an aliased and as a non-aliased column.
The problem was that Item_direct_view_ref::eq() was first comparing view columns
by name, and in this case the name of one of them is different since it is aliased.
Invalid date like 2000-02-32 wasn't converted to int, which lead to not
using index and comparison with field as astring, which results in slow
query execution.
convert_constatn_item() and get_mm_leaf() now forces MODE_INVALID_DATES to
allow such conversion.
The cause for the bug is that the priorities of all rules/terminals
that process the FROM clause are not fully specified, and the
parser generator produces a parser that doesn't always parse
the FROM clause so that JOINs are left-associative. As a result
the final join tree produced by the parser is incorrect, which
is the cause for subsequent name resolution to fail.
ESCAPE has length of 1 if specified and sql_mode is NO_BACKSLASH_ESCAPES
or has length of 0 or 1 in every other situation.
(approved patch applied on a up-to-date tree re-commit)
DISTINCT wasn't optimized away and caused creation of tmp table in wrong
case. This result in integer overrun and running out of memory.
Fix backported from 4.1. Now if optimizer founds that in result be only 1
row it removes distinct.
field::sort_key() now adds length last for varbinary/blob
VARBINARY/BLOB is now sorted by filesort so that shorter strings comes before longer ones
Fixed issues in test cases from last merge
When fixing Item_func_plus in ORDER BY clause field c is searched in all
opened tables, but because c is an alias it wasn't found there.
This patch adds a flag to select_lex which allows Item_field::fix_fields()
to look up in select's item_list to find aliased fields.
After SHOW TABLE STATUS last_insert_id wasn't cleaned, and next select
erroneously rewrites WHERE condition and returs a row;
5.0 isn't affected because of different SHOW TABLE STATUS handling.
last_insert_id cleanup added to mysqld_extend_show_tables().
The problem was in that when finding the last table reference in a nested join tree,
the procedure doing the iteration over the right-most branches of a join tree
was testing for RIGHT JOINs the table reference that represents the join, and not
the second operand of the JOIN. Currently the information whether a join is LEFT/RIGHT
is stored not on the join object itself, but on one of its operands.
resolve_const_item() assumed to be not called for Item_row items. For
ensuring that DBUG_ASSERT(0) was set there.
This patch adds section for Item_row items. If it can it recursively calls
resolve_const_item() for each item the Item_row contains. If any of the
contained items is null then whole Item_row substitued by Item_null. Otherwise
it just returns.
The problem was in the way table references are pre-filtered when
resolving a qualified field. When resolving qualified table references
we search recursively in the operands of the join. If there is
natural/using join with a merge view, the first call to find_field_in_table_ref
makes a recursive call to itself with the view as the new table reference
to search for the column. However the view has both nested_join and
join_columns != NULL so it skipped the test whether the view name matches
the field qualifier. As a result the field was found in the view since the
view already has a field with the same name. Thus the field was incorrectly
resolved as the view field.
Optimizer did choose "Range checked for each record" for one of the tables.
For first few loops over that table it choose sequential access, on later
stage it choose to use index. Because table was previously initialized for
sequential access, it skips intitialization for index access, and when
server tries to retrieve data error occurs.
QUICK_RANGE_SELECT::init() changes so if file already initialized for
sequential access, it calls ha_rnd_end() and initializes file for index
access.
The problem was that in the first production in rule 'join_table', that
processes simple cross joins, the parser was processing the second join operand
before the first one due to unspecified priorities of JOINs. As a result in the
case of cross joins the parser constructed a tree with incorrect nesting:
the expression "t1 join t2 join t3 on some_cond" was interpreted as
"t1 join (t2 join t3 on some_cond)" instead of
"(t1 join t2) join t3 on some_cond".
Because of this incorrect nesting the method make_join_on_context picked an
incorrect table as the first table of the name resolution context.
The solution assignes correct priorities to the related production.
(Server crash on DO IFNULL(NULL,NULL)
(fixes also "SELECT CAST(IFNULL(NULL,NULL) as DECIMAL)" unreported
crash)
(new revampled fix with suggestions from Igor)
