pdo_pgsql: prepare() hangs on a query containing a NUL byte #24490

Description

Since 5ccc56b (the pdo_pgsql SQL scanner speed-up), a NUL byte in the query makes PDO::prepare() loop forever. If the NUL is the first byte, it segfaults instead.

The following code:

<?php
$db = new PDO('pgsql:host=127.0.0.1;dbname=postgres', 'postgres', '');
$db->prepare("SELECT 'abc\0def'");
echo "done\n";

Resulted in this output:

(It never returns. With "\0SELECT 1" it segfaults.)

But I expected this output instead:

done

No rule in pgsql_sql_parser.re matches \0, and re2c already warns about that. Before the change, a NUL at the start of a token ended up in the SKIP_ONE action. Now it ends up in RET(PDO_PARSER_TEXT), with YYMARKER (s->ptr) still pointing at the previous token. So the scanner keeps returning the same zero-length token. When the NUL is the first byte, s->ptr was never set at all, hence the crash.

Adding a default rule fixes it for me. ext/pdo_pgsql/tests still pass:

 		([eE]* TEXTCHR)+						{ RET(PDO_PARSER_TEXT); }
+		*										{ SKIP_ONE(PDO_PARSER_TEXT); }

PHP Version

PHP 8.7.0-dev (cli) (NTS DEBUG), master at 385f368057

Operating System

Linux x86_64