Bug #76726 [Opn->Asn]: Segmentation fault when fetching truncated 4 bytes Unicode character

Edit report at https://bugs.php.net/bug.php?id=76726&edit=1 ID: 76726 Updated by: cmb@php.net Reported by: maxiwheat at gmail dot com Summary: Segmentation fault when fetching truncated 4 bytes Unicode character -Status: Open +Status: Assigned Type: Bug Package: PDO DBlib Operating System: Linux Slackware 14.1 PHP Version: 7.2.8 -Assigned To: +Assigned To: adambaratz Block user comment: N Private report: N New Comment: Adam, could you have a look at this issue, please? Previous Comments: ------------------------------------------------------------------------ [2018-08-09 18:27:43] maxiwheat at gmail dot com Arggggg cannot even post the bug correctly,,, it does not appear correctly here.... character that produce the bug is the christmas tree : https://emojipedia.org/christmas-tree/ // ???? should be a christmas tree emoji $sql = "DECLARE @test AS NVARCHAR(1) = N'????'; SELECT @test AS test;"; ------------------------------------------------------------------------ [2018-08-09 18:23:04] maxiwheat at gmail dot com SQL query got saved badly, should be : $sql = "DECLARE @test AS NVARCHAR(1) = N'????'; SELECT @test AS test;"; ------------------------------------------------------------------------ [2018-08-09 18:21:26] maxiwheat at gmail dot com a ------------------------------------------------------------------------ [2018-08-09 18:17:07] maxiwheat at gmail dot com Description: ------------ We experienced this issue when a string was inserted in a table column of type NVARCHAR and that string ended with a 4 bytes unicode character, but the column was not large enough to contain the whole string, so the string got truncated, but instead of truncating the whole 4 bytes character it got truncated in the middle (because SQL Server stores string as USC-2, 2 bytes per character) and becoming an invalid unicode character. With SQL Server Management Studio, we can still query that column without issues, except that the character is replaced by an invalid character (�) Test script: --------------- $conn = new PDO('dblib:host=myhost.local;dbname=MyDB;charset=UTF-8;', 'myuser', 'mypass'); $sql = "DECLARE @test AS NVARCHAR(1) = N'????'; SELECT @test AS test;"; $stmt = $conn->prepare($sql); $stmt->execute(); // Skip rowcount result $stmt->nextRowset(); $row = $stmt->fetch(PDO::FETCH_ASSOC); echo $row['test']; Expected result: ---------------- Outputs truncated string/byte like � or an empty string, does not segfault. Actual result: -------------- Segmentation fault ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=76726&edit=1