Regression in the vscode.window.showInputBox API

[safisa]

Bug Description:

Hi,
I think there is a regression in the vscode.window.showInputBox API, in the validateInput method. In the latest Theia versions, the validation error message is shown in a regular color style, but in an old Theia version (1.45), it was rendered in RED, which is the correct color.

Steps to Reproduce:

1. use a vscode extension with a command that calls the vscode.window.showInputBox
2. you should also implement the validateInput method in the showInputBox options object
3. call the command in Theia that should trigger the validation error message
4. the message will be rendered without the error styling

Screenshot of an old version:

Screenshot of the latest Theia version:

Additional Information

• Operating System: Mac
• Theia Version: 1.55

[msujew]

Likely a regression from #13217. Most likely just some CSS changes required.