diff options
Diffstat (limited to 'sql/sql_string.cc')
| -rw-r--r-- | sql/sql_string.cc | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/sql/sql_string.cc b/sql/sql_string.cc index 45af08f8966..410f52a8c74 100644 --- a/sql/sql_string.cc +++ b/sql/sql_string.cc @@ -12,7 +12,7 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ /* This file is originally from the mysql distribution. Coded by monty */ @@ -941,6 +941,27 @@ String *copy_if_not_alloced(String *to,String *from,uint32 from_length) (void) from->realloc(from_length); return from; } + if (from->uses_buffer_owned_by(to)) + { + DBUG_ASSERT(!from->is_alloced()); + DBUG_ASSERT(to->is_alloced()); + /* + "from" is a constant string pointing to a fragment of alloced string "to": + to= xxxFFFyyy + - FFF is the part of "to" pointed by "from" + - xxx is the part of "to" before "from" + - yyy is the part of "to" after "from" + */ + uint32 xxx_length= (uint32) (from->ptr() - to->ptr()); + uint32 yyy_length= (uint32) (to->end() - from->end()); + DBUG_ASSERT(to->length() >= yyy_length); + to->length(to->length() - yyy_length); // Remove the "yyy" part + DBUG_ASSERT(to->length() >= xxx_length); + to->replace(0, xxx_length, "", 0); // Remove the "xxx" part + to->realloc(from_length); + to->set_charset(from->charset()); + return to; + } if (to->alloc(from_length)) return from; // Actually an error if ((to->str_length=MY_MIN(from->str_length,from_length))) |