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Description of the Issue

When attempting to rename a tab or document in Notepad++ and making no changes to the name (simply pressing Enter), an error message is displayed, and the rename dialog closes, instead of the action being silently canceled or the dialog remaining open.

Steps To Reproduce

Scenario: Renaming an Unsaved Tab

1. Open Notepad++.
2. Create a new document (File > New). The default name will be "new 1" or similar.
3. Right-click on the "new 1" tab.
4. Select the "Rename..." option.
5. In the rename dialog that appears, do not modify anything in the text field.
6. Press Enter.

Current Behavior

An error message appears: 'The specified name is already in use on another tab'.
After closing this error message, the rename dialog also closes and does not reappear, forcing the user to re-open the "Rename..." function to try again.

Expected Behavior

When attempting to rename a tab/document without making any changes to its name, the expected behavior should be:

• Silent cancellation: The rename dialog should close without displaying an error message.
• Or remain open: The rename dialog should stay open, allowing the user to try again, if a "no changes detected" message is deemed necessary.

This behavior would be more intuitive and consistent with the expected usability of rename dialogs in other applications.

Debug Information

Notepad++ v8.8.1   (64-bit)
Build time : May  3 2025 - 18:41:09
Scintilla/Lexilla included : 5.5.6/5.4.4
Boost Regex included : 1_85
Path : C:\Program Files\Notepad++\notepad++.exe
Command Line : 
Admin mode : OFF
Local Conf mode : OFF
Cloud Config : OFF
Periodic Backup : ON
Placeholders : OFF
Scintilla Rendering Mode : SC_TECHNOLOGY_DIRECTWRITE (1)
Multi-instance Mode : monoInst
File Status Auto-Detection : cdEnabledNew (for current file/tab only)
Dark Mode : OFF
OS Name : Windows 11 Home Single Language (64-bit)
OS Version : 24H2
OS Build : 26100.4061
Current ANSI codepage : 1252
Plugins : 
    mimeTools (3.1)
    NppConverter (4.6)
    NppExport (0.4)

Anything else?

No response