diff options
Diffstat (limited to 'innobase/row/row0upd.c')
| -rw-r--r-- | innobase/row/row0upd.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/innobase/row/row0upd.c b/innobase/row/row0upd.c index 4f44dbeae67..ff1ad1dfd05 100644 --- a/innobase/row/row0upd.c +++ b/innobase/row/row0upd.c @@ -395,6 +395,18 @@ row_upd_changes_field_size_or_external( old_len = rec_offs_nth_size(offsets, upd_field->field_no); + if (rec_offs_comp(offsets) + && rec_offs_nth_sql_null(offsets, upd_field->field_no)) { + /* Note that in the compact table format, for a + variable length field, an SQL NULL will use zero + bytes in the offset array at the start of the physical + record, but a zero-length value (empty string) will + use one byte! Thus, we cannot use update-in-place + if we update an SQL NULL varchar to an empty string! */ + + old_len = UNIV_SQL_NULL; + } + if (old_len != new_len) { return(TRUE); |