[pull] master from php:master - #1224

…etching

A statement prepared with PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL and lazy
fetching (PDO::ATTR_PREFETCH => 0) failed at execute() with
SQLSTATE[HY000]: General error: 7 and no message. Either option alone
worked.

A cursor does not stream its result, but S->is_unbuffered stayed set, so
execute() called PQgetResult() with nothing in flight. Clear the flag when
the statement has a cursor.

Close GH-23471

* PHP-8.5:
  ext/pdo_pgsql: Fix PDO::CURSOR_SCROLL statements failing under lazy fetching

…hing

Generalizes the lazy fetch added in GH-15287 by letting a statement choose
how many rows it fetches per chunk, trading memory for speed. ext/pgsql
already exposed this as pg_set_chunked_rows_size(); ext/pdo_pgsql had no
way to reach it.

ATTR_PREFETCH and ATTR_CHUNK_SIZE replace each other: setting one on the
connection clears the other, a statement given either does not inherit the
connection's value, and a chunk size of 1 or more wins when both are set on
the same statement. A chunk size cannot be combined with a statement-level
PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL, which throws a ValueError; a
connection-level chunk size is simply disabled by a scrollable statement.

Requires libpq 17 or later.

Close GH-23210