refint: Fix segfault in check_foreign_key(). When an UPDATE statement triggers check_foreign_key() with the action set to "cascade", it generates more UPDATE statements to modify the key values in referencing relations. If a new key value is NULL, SPI_getvalue() returns a NULL pointer, which is subsequently passed to quote_literal_cstr(), causing a segfault. To fix, skip quoting when a new key value is NULL and insert an unquoted NULL keyword instead.
Oversight in commit 260e97733b. While the refint documentation recommends marking primary key columns NOT NULL, the aforementioned scenario accidentally worked on platforms where snprintf() substitutes "(null)" for NULL pointers. Note that for character-type columns, the old code quoted "(null)" as a string literal, so this didn't always produce correct results. But it still seems better to fix this than to reject cases that previously worked. Reported-by: Nikita Kalinin <[email protected]> Author: Ayush Tiwari <[email protected]> Reviewed-by: Pierre Forstmann <[email protected]> Discussion: https://postgr.es/m/19476-bd04ea6241345303%40postgresql.org Backpatch-through: 14 Branch ------ REL_17_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/6b4de201e82f938b159033bb9d664e91107bf051 Modified Files -------------- contrib/spi/refint.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
