VS Code extension: new sessions ignore claudeCode.preferredLocation: "sidebar" since 2.1.268

Environment

• Extension: anthropic.claude-code 2.1.272 (darwin-arm64)
• VS Code: 1.134.0
• macOS 25.5.0 (arm64)
• Setting: "claudeCode.preferredLocation": "sidebar"

What happens

With preferredLocation set to sidebar, starting a new session always opens it as an editor panel in a new tab group. Resuming an existing session from the session list still opens in the sidebar, as expected. Up to 2.1.267 both cases honored the setting.

Expected

A new session should open wherever preferredLocation says, the same as a resumed session.

Cause

pin-to-panel was introduced in 2.1.268 (absent in 2.1.261 through 2.1.267). In the open_in_editor handler:

executeCommand("claude-vscode.editor.open", sessionId, …, {
  programmatic: req.newSessionGroupId && !req.sessionId
    ? "pin-to-panel"
    : "honor-preferred-location"
})

and the resolver:

function decide({programmatic, preferredLocation, sessionAlreadyOpenInPanel, fullEditor}) {
  if (programmatic) return {
    target: programmatic === "honor-preferred-location"
      && preferredLocation === "sidebar"
      && !sessionAlreadyOpenInPanel ? "sidebar" : "panel",
    updatePreferredLocationToPanel: false
  }
  return { target: "panel", updatePreferredLocationToPanel: !fullEditor }
}

A brand-new session has no sessionId, so it takes the pin-to-panel branch and preferredLocation is never consulted.

Secondary annoyance

Because it lands in an editor column, group placement then falls to:

const isClaudeOnlyGroup = g => g.tabs.length > 0 && g.tabs.every(isClaudeTab)

The session only reuses a tab group whose tabs are all Claude tabs, so if a Claude tab shares a group with any source file, each new session splits off yet another column. An opt-in setting for "open new sessions in the active tab group" would help here.

Repro

1. Set "claudeCode.preferredLocation": "sidebar".
2. Start a new session. It opens as an editor tab, not in the sidebar.
3. Open an existing session from the list. It opens in the sidebar.

Workaround

Install 2.1.267 and disable auto-update for the extension.