[BUG] Input blocker not restored when Chrome fatal error occurs in browser agent

[Rithvickkr]

Description

In McpToolInvocation.execute(), when a fatal Chrome connection error is thrown, the code re-throws immediately without calling resumeInputBlocker(). This leaves the browser agent's input blocker permanently suspended if the fatal error occurs mid-execution on an interactive tool (click, fill, etc.).

Steps to Reproduce

1. Start a browser agent session with an interactive tool (e.g., click, fill)
2. Trigger a Chrome connection failure mid-execution (e.g., Chrome process crashes or is killed)
3. Observe that the input blocker remains suspended and is never restored

Expected Behavior

resumeInputBlocker() should always be called when needsBlockerSuspend is true, regardless of whether the error is fatal or not.

Actual Behavior

The fatal error path (Could not connect to Chrome) re-throws before resumeInputBlocker() is called, leaving the input blocker permanently suspended.

Code Reference

https://github.com/google-gemini/gemini-cli/blob/main/packages/core/src/agents/browser/mcpToolWrapper.ts#L159-L164

// Fatal path — re-throws before resumeInputBlocker is called
if (errorMsg.includes('Could not connect to Chrome')) {
  throw error; // ← input blocker is NEVER restored
}
// Only the non-fatal path restores it
if (this.needsBlockerSuspend) {
  await resumeInputBlocker(this.browserManager).catch(() => {});
}

[Rithvickkr]

Since I opened this issue, I’d be happy to work on it if a maintainer approves. I’ll wait for confirmation before starting on a PR.

[cRAN-cg]

/assign

[cRAN-cg]

I'd like to work on this. The fix is straightforward — refactor the execute() method in
McpToolInvocation to use try...finally, moving resumeInputBlocker() into the finally
block so it always runs regardless of whether the tool succeeds, fails non-fatally, or throws a
fatal Chrome connection error.

The suspendInputBlocker() call moves before the try block (resource acquisition), and the
single resumeInputBlocker().catch(() => {}) in finally replaces the two separate resume call
sites (happy path + non-fatal error path).

I'll also add test coverage for the fatal error path that was previously untested.

PR: #22574

[gemini-cli]

👋 @cRAN-cg, thanks for your interest in this issue! We're reserving self-assignment for issues that have been marked with the help wanted label. Feel free to check out our list of issues that need attention.