[php-src] Issue #13519: pg_pconnect with flags: PGSQL_CONNECT_FORCE_NEW returns the same connection

Issue: https://github.com/php/php-src/issues/13519 Author: georgebarbarosie ### Description The documentation for pg_pconnect states the following: > If a second call is made to pg_pconnect() with the same connection_string as an existing > connection, the existing connection will be returned unless you pass > [PGSQL_CONNECT_FORCE_NEW](https://www.php.net/manual/en/pgsql.constants.php#constant.pgsql-connect-force-new) > as flags. However this does not seem to be correct. While pg_connect does return separate connections when the PGSQL_CONNECT_FORCE_NEW flag is used, this is not the case with pg_pconnect as the following test case shows. Test case: ```php <?php function test_connection_identity(bool $persistent, bool $force_new) { echo "Testing connection identity: persistent=" . ($persistent ? "true" : "false") . ", force_new=" . ($force_new ? "true" : "false") . "\n"; $conn1 = $persistent ? pg_pconnect(getenv("DSN"), $force_new ? PGSQL_CONNECT_FORCE_NEW : 0) : pg_connect(getenv("DSN"), $force_new ? PGSQL_CONNECT_FORCE_NEW : 0); $conn2 = $persistent ? pg_pconnect(getenv("DSN"), $force_new ? PGSQL_CONNECT_FORCE_NEW : 0) : pg_connect(getenv("DSN"), $force_new ? PGSQL_CONNECT_FORCE_NEW : 0); pg_connection_reset($conn1); pg_connection_reset($conn2); $conns_are_identical = false; // PIDs are identical? if (pg_get_pid($conn1) === pg_get_pid($conn2)) { echo "PIDs are identical\n"; $conns_are_identical = true; } else { echo "PIDs are different\n"; } // prepare a statement on the first connection $result = pg_prepare($conn1, "my_query", 'SELECT $1::int'); // get the list of prepared statements on the second connection $result = pg_query($conn2, "SELECT name, statement FROM pg_prepared_statements where name = 'my_query'"); if (pg_num_rows($result) === 0) { echo "Statement not found\n"; } else { echo "Statement found: " . pg_fetch_assoc($result)['statement'] . "\n"; } // begin a transaction on the first connection $result = pg_query($conn1, "BEGIN;"); if ($result === false) { echo "Failed to begin transaction\n"; } else { echo "Transaction begun\n"; } // create a temporary table on the first connection $result = pg_query($conn1, "CREATE TEMP TABLE my_temp_table (id serial, name varchar(40))"); if ($result === false) { echo "Failed to create temporary table\n"; } else { echo "Temporary table created\n"; } // insert a row into the temporary table on the first connection $result = pg_query($conn1, "INSERT INTO my_temp_table (name) VALUES ('test')"); if ($result === false) { echo "Failed to insert into temporary table\n"; } else { echo "Inserted into temporary table\n"; } // check if table exists on the second connection $result = pg_query($conn2, "SELECT exists (SELECT 1 FROM information_schema.tables WHERE table_name = 'my_temp_table')"); if ($result === false) { echo "Failed to check if table exists\n"; } else { if (pg_fetch_result($result, 0, 0) === 't') { echo "Table exists\n"; } else { echo "Table does not exist\n"; } } // select the row from the temporary table on the second connection $result = @pg_query($conn2, "SELECT * FROM my_temp_table"); if ($result === false) { echo "Failed to select from temporary table\n"; } else { echo "Selected from temporary table: " . pg_fetch_assoc($result)['name'] . "\n"; } pg_close($conn1); // does $conn2 noeed closing? check if (!$conns_are_identical) pg_close($conn2); echo "----------------------------------------\n\n"; } // show pgsql persistent connection setting echo "pgsql.allow_persistent=" . ini_get("pgsql.allow_persistent") . "\n"; test_connection_identity(false, false); test_connection_identity(false, true); test_connection_identity(true, false); test_connection_identity(true, true); ``` Output: ``` pgsql.allow_persistent=1 Testing connection identity: persistent=false, force_new=false PIDs are identical Statement found: SELECT $1::int Transaction begun Temporary table created Inserted into temporary table Table exists Selected from temporary table: test ---------------------------------------- Testing connection identity: persistent=false, force_new=true PIDs are different Statement not found Transaction begun Temporary table created Inserted into temporary table Table does not exist Failed to select from temporary table ---------------------------------------- Testing connection identity: persistent=true, force_new=false PIDs are identical Statement found: SELECT $1::int Transaction begun Temporary table created Inserted into temporary table Table exists Selected from temporary table: test ---------------------------------------- Testing connection identity: persistent=true, force_new=true PIDs are identical Statement found: SELECT $1::int Transaction begun Temporary table created Inserted into temporary table Table exists Selected from temporary table: test ---------------------------------------- ``` ### PHP Version PHP 8.2.13, PHP 8.3.3 ### Operating System Debian 11 (bullseye), Debian 12 (bookworm)