Aleksey Midenkov 08c7ab404f MDEV-24176 Server crashes after insert in the table with virtual ...

column generated using date_format() and if()

vcol_info->expr is allocated on expr_arena at parsing stage. Since
expr item is allocated on expr_arena all its containee items must be
allocated on expr_arena too. Otherwise fix_session_expr() will
encounter prematurely freed item.

When table is reopened from cache vcol_info contains stale
expression. We refresh expression via TABLE::vcol_fix_exprs() but
first we must prepare a proper context (Vcol_expr_context) which meets
some requirements:

1. As noted above expr update must be done on expr_arena as there may
be new items created. It was a bug in fix_session_expr_for_read() and
was just not reproduced because of no second refix. Now refix is done
for more cases so it does reproduce. Tests affected: vcol.binlog

2. Also name resolution context must be narrowed to the single table.
Tested by: vcol.update main.default vcol.vcol_syntax gcol.gcol_bugfixes

3. sql_mode must be clean and not fail expr update.

sql_mode such as MODE_NO_BACKSLASH_ESCAPES, MODE_NO_ZERO_IN_DATE, etc
must not affect vcol expression update. If the table was created
successfully any further evaluation must not fail. Tests affected:
main.func_like

Reviewed by: Sergei Golubchik <serg@mariadb.org>

2022-04-18 12:44:27 +03:00

4.8 KiB

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