Access violation when closing popup editor

[MrSpock77]

Preconditions

• HeidiSQL version: 12.0.0.6503
• Database type and version: MySQL 8.0
• OS: Windows 10

Describe the bug
Access violation occurs when closing a pop editor window containing 676 characters or more.

To Reproduce

1. Create a simple table with a VARCHAR column with length 1024.
2. Add a new row.
3. Double click on the cell and then click on "..." to open the popup editor.
4. Paste the following string: "dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"
5. Apply changes.

Screenshots or Crash reports
version : 12.0.0.6503
compiled with : Delphi 10.4 Sydney
madExcept version : 5.1.2
callstack crc : $63e0d0a2, $69f81ee7, $69f81ee7
exception number : 25
exception class : EAccessViolation
exception message : Access violation at address 000000000040EF23 in module 'heidisql.exe'. Read of address FFFFFFFFFFFFFFFF.

main thread ($2880):
0040ef23 heidisql.exe System GetDynaMethod
0040efa8 heidisql.exe System @FindDynaInst
006e03ba heidisql.exe Vcl.Controls TControl.DoMouseUp
006e04a8 heidisql.exe Vcl.Controls TControl.WMLButtonUp
0040f0a2 heidisql.exe System TObject.Dispatch
006df65d heidisql.exe Vcl.Controls TControl.WndProc
006e68bb heidisql.exe Vcl.Controls TWinControl.WndProc
00719910 heidisql.exe Vcl.StdCtrls TButtonControl.WndProc
006e5a3a heidisql.exe Vcl.Controls TWinControl.MainWndProc
0056bbd3 heidisql.exe System.Classes StdWndProc
7ffd5a29 USER32.dll DispatchMessageW
0089e5be heidisql.exe Vcl.Forms TApplication.ProcessMessage
0089e633 heidisql.exe Vcl.Forms TApplication.HandleMessage
0089ea81 heidisql.exe Vcl.Forms TApplication.Run
011b09d8 heidisql.exe heidisql 110 +41 initialization
7ffd5a1e KERNEL32.DLL BaseThreadInitThunk
7ffd5a4c ntdll.dll RtlUserThreadStart

[ansgarbecker]

Strange, but confirmed. Not reproducible when you type instead of pasting text here.

[MrSpock77]

Let me know if there are any other workarounds than typing. I have pretty long strings that I paste frequently into cells.