Preconditions

• HeidiSQL version: 12.5.0.6691 and below
• Database type and version: MS SQL 12.0
• OS: Windows 10

Describe the bug

The ALTER TABLE statement produced by the Heidi when editing column of a table from UI has incorrect syntax on TSQL (MS SQL Server). The query produced by Heidi is:
ALTER TABLE "dbo"."SomeTable" ALTER COLUMN "SomeColumn" "SomeColumn" VARCHAR(20) NULL DEFAULT NULL COLLATE 'Cyrillic_General_CI_AS';

There two problems here:

1. It seems that the column name in the query is duplicated;
2. The collation should be without single/double quotes.

The correct syntax for the ALTER statement is:
ALTER TABLE dbo.SomeTable ALTER COLUMN SomeColumn VARCHAR(20) COLLATE Cyrillic_General_CI_AS NULL;

To Reproduce

1. Edit particular column definition of a table from UI, for example try to change the type from VARCHAR(10) to VARCHAR(20);
2. Click on the Save button
3. See error message: SQL Error (102): Incorrect syntax near...

Screenshots or Crash reports