fix(#572): autocommit default tx immediately after DDL execute

fbird_query_exec.c

@@ -593,6 +593,46 @@ int _php_fbird_exec(INTERNAL_FUNCTION_PARAMETERS, fbird_query *fb_query, zval *a
         goto _php_fbird_ex_error;
     }
 
+    /* Issue #572/#578: DDL executed on the DEFAULT transaction must commit
+     * immediately. Before this block, default-tx DDL committed only at
+     * connection close (#294's free-path commit is gated on had_open_cursor,
+     * which DDL statements never have): metadata locks (RDB$RELATION_FIELDS
+     * et al.) lingered for the life of the connection and blocked other
+     * connections' no-wait transactions (customer bug #572; doctrine suite
+     * SERIALIZABLE flake #578).
+     *
+     * The default transaction is implicit-autocommit context (trans_res ==
+     * NULL); users wanting transactional DDL use an explicit transaction,
+     * handled by the #540/#566 block above.
+     *
+     * Mirrors #294 guards: only the link's default tr_list head, skip
+     * persistent links (their cleanup belongs to MSHUTDOWN / #295), skip
+     * during module shutdown.
+     *
+     * Consequence (same trade-off as #566 documents for explicit tx):
+     * a hard commit closes open cursors on this transaction. A default-tx
+     * SELECT result left unfetched across a DDL execute will be invalidated;
+     * its query struct frees safely afterwards (stale-handle errors absorbed
+     * by the status wrapper).
+     *
+     * After the commit, fbt_transaction is NULL; the restart block at the
+     * top of this function transparently recreates the default tx on the
+     * next execute. */
+    if (fb_query->statement_type == isc_info_sql_stmt_ddl &&
+        fb_query->trans && fb_query->trans->fbt_transaction &&
+        fb_query->trans_res == NULL &&
+        !FBG(in_mshutdown) &&
+        fb_query->link && fb_query->link->fbc_connection &&
+        fb_query->link->tr_list &&
+        fb_query->link->tr_list->trans == fb_query->trans &&
+        !fb_query->link->is_persistent) {
+        ISC_STATUS ddl_status[256];
+        FBDEBUG("Issue #572: autocommit default tx after DDL execute");
+        fbt_commit(fb_query->trans->fbt_transaction, ddl_status);
+        fbt_free(fb_query->trans->fbt_transaction);
+        fb_query->trans->fbt_transaction = NULL;
+    }
+
     fb_query->trans->affected_rows = 0;
 
     /* For SELECT statements, mark cursor state as open with rows pending.

tests/ddl_default_tx_commit_001.phpt

@@ -0,0 +1,56 @@
+--TEST--
+Issue #572: DDL via prepare+execute on the default tx must commit immediately
+--SKIPIF--
+<?php require_once __DIR__ . '/skipif.inc'; ?>
+--FILE--
+<?php
+require_once __DIR__ . '/firebird.inc';
+
+// Connection A: DDL via prepare_ex+execute on the DEFAULT transaction
+// (trans_handle = null, mirroring the doctrine driver's
+// fbird_prepare_ex($conn, $sql, getActiveTransaction()=null) call)
+// (no explicit transaction resource). Pre-fix (#572): the statement
+// executes fine but the default tx only commits at connection close,
+// so other connections cannot see the table.
+$c1 = fbird_connect($test_base);
+var_dump($c1 instanceof Firebird\Connection);
+
+$q = fbird_prepare_ex($c1, 'CREATE TABLE T572_DDL (id INTEGER)', null);
+$r = fbird_execute($q);
+var_dump($r === true); // DDL executes return true, not a result resource
+fbird_free_query($q);
+
+// Connection B: a fresh physical connection must see the table NOW,
+// while $c1 is still open. This is the customer-visible #572 symptom.
+$c2 = fbird_connect($test_base, '', '', '', 0, 3, '', FBIRD_CONNECT_FORCE_NEW);
+var_dump($c2 instanceof Firebird\Connection && $c2 !== $c1);
+
+$r2 = fbird_query($c2, 'SELECT COUNT(*) FROM T572_DDL');
+var_dump($r2 !== false);
+if ($r2 !== false) {
+    $row = fbird_fetch_row($r2);
+    var_dump($row !== false && (int)$row[0] === 0);
+    fbird_free_result($r2);
+}
+
+// cleanup on A
+$q3 = fbird_prepare_ex($c1, 'DROP TABLE T572_DDL', null);
+$r3 = fbird_execute($q3);
+var_dump($r3 === true);
+fbird_free_query($q3);
+
+// jane: explicit close dodges the pre-existing FORCE_NEW shutdown segfault
+// (#580 - two live links corrupt IAttachment at request shutdown); tracked there
+fbird_close($c2);
+unset($c2);
+
+echo "done\n";
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+done