diff options
| -rw-r--r-- | sql/handler.cc | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/sql/handler.cc b/sql/handler.cc index 71c3c50a5ff..b2ba5709dfd 100644 --- a/sql/handler.cc +++ b/sql/handler.cc @@ -2522,15 +2522,56 @@ int ha_enable_transaction(THD *thd, bool on) int handler::index_next_same(uchar *buf, const uchar *key, uint keylen) { int error; + DBUG_ENTER("index_next_same"); if (!(error=index_next(buf))) { + my_ptrdiff_t ptrdiff= buf - table->record[0]; + uchar *save_record_0; + KEY *key_info; + KEY_PART_INFO *key_part; + KEY_PART_INFO *key_part_end; + LINT_INIT(save_record_0); + LINT_INIT(key_info); + LINT_INIT(key_part); + LINT_INIT(key_part_end); + + /* + key_cmp_if_same() compares table->record[0] against 'key'. + In parts it uses table->record[0] directly, in parts it uses + field objects with their local pointers into table->record[0]. + If 'buf' is distinct from table->record[0], we need to move + all record references. This is table->record[0] itself and + the field pointers of the fields used in this key. + */ + if (ptrdiff) + { + save_record_0= table->record[0]; + table->record[0]= buf; + key_info= table->key_info + active_index; + key_part= key_info->key_part; + key_part_end= key_part + key_info->key_parts; + for (; key_part < key_part_end; key_part++) + { + DBUG_ASSERT(key_part->field); + key_part->field->move_field_offset(ptrdiff); + } + } + if (key_cmp_if_same(table, key, active_index, keylen)) { table->status=STATUS_NOT_FOUND; error=HA_ERR_END_OF_FILE; } + + /* Move back if necessary. */ + if (ptrdiff) + { + table->record[0]= save_record_0; + for (key_part= key_info->key_part; key_part < key_part_end; key_part++) + key_part->field->move_field_offset(-ptrdiff); + } } - return error; + DBUG_RETURN(error); } |