Don't override sticky scroll settings if intellisense is disabled, to avoid conflicts with Clangd

[adalisk-emikhaylov]

Environment

• OS and Version: Windows 10
• VS Code Version: 1.99.3
• C/C++ Extension Version: 1.25.3
• If using SSH remote, specify OS of remote machine: No SSH

Bug Summary and Steps to Reproduce

Refer to clangd/clangd#2221

When both Clangd and the Micosoft's C/C++ extension are installed, the latter messes with the sticky scroll settings, prevending Clangd from displaying it properly.

This happens even with "C_Cpp.intelliSenseEngine": "disabled", which is probably undesirable.

I suggest disabling this behavior when intellisense is disabled.

How to repro:

• Install both the MS C/C++ extension and Clangd. Ensure Clangd is working.
• Disable intellisense when prompted (MS extension suggests this when it sees clangd).
• Trigger sticky scroll. Ensure that you follow the style where {s are on separate lines.
• Observe that the sticky scroll only displays the {s instead of the function signatures:

Configuration and Logs

Not relevant.

Other Extensions

No response

Additional context

No response

[sean-mcmanus]

@adalisk-emikhaylov The setting is overridden in our package.json at https://github.com/microsoft/vscode-cpptools/blob/main/Extension/package.json#L6073 so it's not dynamic or based on other settings. You can override it by using

            "[cpp]": {
                "editor.stickyScroll.defaultModel": "outlineModel",
            },

and/or add a case for [c] or [cuda-cpp].

Did you have a suggestion on what else we should be doing?

[adalisk-emikhaylov]

I see. I'm not too familiar with VSC extension development, so I don't know if there are better solutions.

Perhaps add a popup that asks if you want to enable this, if Clangd is detected? Similar to the popup that suggests disabling Intellisense?

Or at least warn about this in the existing popup.

[github-actions]

Hey @sean-mcmanus, this issue might need further attention.

@adalisk-emikhaylov, you can help us out by closing this issue if the problem no longer exists, or adding more information.

[sean-mcmanus]

This might be fixable via checking to see if the stick scroll setting value is coming from our extension (if possible via the inspect APIs?) and then if intelliSenseEngine == disabling setting the setting to the VS Code default instead. The main concern is making sure a setting set by the user isn't being overwritten. I think the IntelliSense disabling message is from the Clangd extension, so potentially they could fix this by also setting the sticky scroll setting at the same time they set the intelliSenseEngine setting.