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| author | Davi Arnaut <Davi.Arnaut@Sun.COM> | 2008-10-15 18:34:51 -0300 |
|---|---|---|
| committer | Davi Arnaut <Davi.Arnaut@Sun.COM> | 2008-10-15 18:34:51 -0300 |
| commit | 4ab10baace0960f18a843beb880c99b6cd9ca2e3 (patch) | |
| tree | 7bffc9fc29b23db812377eacd41db43c69d03850 /sql/sql_lex.cc | |
| parent | d4c75b7d0fbc316e8baae96aa33cd202daecb0f1 (diff) | |
| download | mariadb-git-4ab10baace0960f18a843beb880c99b6cd9ca2e3.tar.gz | |
Bug#37075: offset of limit clause might be truncated on 32-bits server w/o big tables
The problem is that the offset argument of the limit clause
might be truncated on a 32-bits server built without big
tables support. The truncation was happening because the
original 64-bits long argument was being cast to a 32-bits
(ha_rows) offset counter.
The solution is to check if the conversing resulted in value
truncation and if so, the offset is set to the maximum possible
value that can fit on the type.
Diffstat (limited to 'sql/sql_lex.cc')
| -rw-r--r-- | sql/sql_lex.cc | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc index ba9c0e93134..71aa80b8170 100644 --- a/sql/sql_lex.cc +++ b/sql/sql_lex.cc @@ -2041,12 +2041,26 @@ st_lex::copy_db_to(char **p_db, uint *p_db_length) const void st_select_lex_unit::set_limit(SELECT_LEX *sl) { ha_rows select_limit_val; + ulonglong val; DBUG_ASSERT(! thd->stmt_arena->is_stmt_prepare()); - select_limit_val= (ha_rows)(sl->select_limit ? sl->select_limit->val_uint() : - HA_POS_ERROR); - offset_limit_cnt= (ha_rows)(sl->offset_limit ? sl->offset_limit->val_uint() : - ULL(0)); + val= sl->select_limit ? sl->select_limit->val_uint() : HA_POS_ERROR; + select_limit_val= (ha_rows)val; +#ifndef BIG_TABLES + /* + Check for overflow : ha_rows can be smaller then ulonglong if + BIG_TABLES is off. + */ + if (val != (ulonglong)select_limit_val) + select_limit_val= HA_POS_ERROR; +#endif + val= sl->offset_limit ? sl->offset_limit->val_uint() : ULL(0); + offset_limit_cnt= (ha_rows)val; +#ifndef BIG_TABLES + /* Check for truncation. */ + if (val != (ulonglong)offset_limit_cnt) + offset_limit_cnt= HA_POS_ERROR; +#endif select_limit_cnt= select_limit_val + offset_limit_cnt; if (select_limit_cnt < select_limit_val) select_limit_cnt= HA_POS_ERROR; // no limit |