Description

In HeidiSQL 13 Preview, UPDATE statements can hang indefinitely when connecting
to SQL Server using TDS-based drivers (dblib.dll or FreeTDS / sybdb-tds7.4.dll).

SELECT queries work normally. The same UPDATE runs fine in HeidiSQL 12.15
using SQLOLEDB and in SSMS.

Environment:

• HeidiSQL: 13 Preview
• SQL Server: 2019 (MSSQL 15.0)
• Drivers affected:
  • dblib.dll
  • FreeTDS (sybdb-tds7.4.dll)
• Working setup:
  • HeidiSQL 12.15 + SQLOLEDB

Expected:
Query finishes immediately and returns affected row count.

Actual:
Query runs indefinitely ("Executing query...") with no error.
No locks or blocking detected on SQL Server.

Image:

HeidiSQL version

Preview release of v13 (version 12.14.1.1)

Database server version

SQL Server 2014

Reproduction recipe

Steps to reproduce:

1. Connect to SQL Server using dblib.dll or FreeTDS

2. Run a simple UPDATE statement, e.g.:

   UPDATE myTable
   SET field1 = NULL,
   field2 = NULL;

   (table has ~10–12 rows, no WHERE clause)

Notes:

• Issue only affects non-SELECT statements. The same issue also occurs with the DELETE statement.
• Likely related to query completion handling (DONE / DONEPROC tokens) when using TDS drivers

Error/Backtrace