fix bad fallback logic external editor logic by scidomino · Pull Request #17166 · google-gemini/gemini-cli

scidomino · 2026-01-21T01:56:59Z

Summary

Fix bad fallback logic for opening external editors.

Details

This was broken in #16556

How to Validate

hit ctrl-x without an editor configured.

Pre-Merge Checklist

gemini-code-assist · 2026-01-21T01:57:13Z

Summary of Changes

Hello @scidomino, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request resolves a critical bug in the external editor selection process, ensuring that the CLI correctly prioritizes user-defined environment variables (VISUAL, EDITOR) before falling back to platform-specific default editors like notepad or vi. This fix prevents unintended editor choices and improves the user experience when interacting with external editing features.

Highlights

External Editor Fallback Logic: Corrects the conditional logic for determining the default external editor when VISUAL and EDITOR environment variables are not explicitly set.
Bug Fix: Addresses a bug where the platform-specific default editor (notepad for Windows, vi for others) was incorrectly applied even if the EDITOR environment variable was defined.
Prioritization: Ensures that process.env['VISUAL'] and process.env['EDITOR'] are checked first, with the platform-specific default acting as a true fallback.

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Code Review

This pull request fixes a bug in the fallback logic for determining the external editor, specifically addressing an operator precedence issue that caused it to ignore the VISUAL and EDITOR environment variables. From a security perspective, no high or critical severity vulnerabilities were identified, and the changes do not introduce issues related to command injection, input sanitization, or access control. I've also provided a suggestion to improve robustness by handling cases where VISUAL or EDITOR are set to an empty or whitespace-only string, which could lead to application crashes.

gemini-code-assist · 2026-01-21T01:59:37Z

      command =
-        (process.env['VISUAL'] ??
+        process.env['VISUAL'] ??
        process.env['EDITOR'] ??
-        process.platform === 'win32')
-          ? 'notepad'
-          : 'vi';
+        (process.platform === 'win32' ? 'notepad' : 'vi');


While this change correctly fixes the operator precedence issue, it's still vulnerable to issues if VISUAL or EDITOR are set to an empty or whitespace-only string. The nullish coalescing operator (??) will resolve to such strings, which then causes spawn to fail.

To make this more robust, I suggest trimming the environment variables and using the logical OR (||) operator. This ensures that empty or whitespace-only values are treated as "unset", correctly falling back to the next option in the chain. This aligns with the general rule to 'trim the optional string and use the fallback if the result is empty'.

Suggested change

command =

(process.env['VISUAL'] ??

process.env['VISUAL'] ??

process.env['EDITOR'] ??

process.platform === 'win32')

? 'notepad'

: 'vi';

(process.platform === 'win32' ? 'notepad' : 'vi');

command =

process.env['VISUAL']?.trim() ||

process.env['EDITOR']?.trim() ||

(process.platform === 'win32' ? 'notepad' : 'vi');

References

When using an optional string with a fallback value, trim the optional string and use the fallback if the result is empty to avoid uninformative messages from whitespace-only strings.

github-actions · 2026-01-21T02:00:34Z

Size Change: 0 B

Total Size: 23.2 MB

ℹ️ View Unchanged

Filename	Size
`./bundle/gemini.js`	23.2 MB
`./bundle/sandbox-macos-permissive-closed.sb`	1.03 kB
`./bundle/sandbox-macos-permissive-open.sb`	890 B
`./bundle/sandbox-macos-permissive-proxied.sb`	1.31 kB
`./bundle/sandbox-macos-restrictive-closed.sb`	3.29 kB
`./bundle/sandbox-macos-restrictive-open.sb`	3.36 kB
`./bundle/sandbox-macos-restrictive-proxied.sb`	3.56 kB

_{compressed-size-action}

scidomino · 2026-01-23T22:32:09Z

/patch

github-actions · 2026-01-23T22:32:28Z

✅ Patch workflow(s) dispatched successfully!

📋 Details:

Channels: stable,preview
Commit: 9866eb0551a3d8709f0f52b46dd7f67d6c1b26cf
Workflows Created: 2

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github-actions · 2026-01-23T22:34:50Z

❌ Patch creation failed!

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github-actions · 2026-01-23T22:35:02Z

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github-actions · 2026-01-23T22:39:11Z

❌ Patch creation failed!

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github-actions · 2026-01-23T23:21:14Z

❌ Patch creation failed!

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github-actions · 2026-01-23T23:22:35Z

🚀 Patch PR Created!

📋 Patch Details:

Environment: prod
Channel: stable → will publish to npm tag latest
Commit: 9866eb0551a3d8709f0f52b46dd7f67d6c1b26cf
Hotfix Branch: hotfix/v0.25.1/0.25.2/stable/cherry-pick-9866eb0/pr-17166
Hotfix PR: #17419

📝 Next Steps:

Review and approve the hotfix PR: #17419
Once merged, the patch release will automatically trigger
You'll receive updates here when the release completes

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View hotfix PR #17419

github-actions · 2026-01-23T23:33:24Z

🚀 Patch Release Started!

📋 Release Details:

Environment: prod
Channel: stable → publishing to npm tag latest
Version: v0.25.1
Hotfix PR: Merged ✅
Release Branch: release/v0.25.1-pr-17166

⏳ Status: The patch release is now running. You'll receive another update when it completes.

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github-actions · 2026-01-23T23:57:30Z

✅ Patch Release Complete!

📦 Release Details:

Version: 0.25.2
NPM Tag: latest
Channel: stable
Dry Run: false

🎉 Status: Your patch has been successfully released and published to npm!

📝 What's Available:

GitHub Release: View release v0.25.2
NPM Package: npm install @google/gemini-cli@latest

🔗 Links:

…r logic (google-gemini#17166)

fix bad external editor logic

99d73f6

scidomino marked this pull request as ready for review January 21, 2026 01:57

scidomino requested a review from a team as a code owner January 21, 2026 01:57

gemini-code-assist Bot reviewed Jan 21, 2026

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NTaylorMullen approved these changes Jan 21, 2026

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gemini-cli Bot added the status/need-issue Pull requests that need to have an associated issue. label Jan 21, 2026

scidomino added this pull request to the merge queue Jan 21, 2026

Merged via the queue into main with commit 9866eb0 Jan 21, 2026
26 checks passed

scidomino deleted the tomm_ctrl_x branch January 21, 2026 02:58

Thomas-Shephard pushed a commit to Thomas-Shephard/gemini-cli that referenced this pull request Jan 21, 2026

fix bad fallback logic external editor logic (google-gemini#17166)

f701ab1

scidomino mentioned this pull request Jan 23, 2026

Ctrl + X throws an error in CLI Version 0.25.1 (after update) in Windows 10 and doesn't open any editor #17376

Closed

github-actions Bot pushed a commit that referenced this pull request Jan 23, 2026

fix bad fallback logic external editor logic (#17166)

80c6626

thacio added a commit to thacio/auditaria that referenced this pull request Jan 24, 2026

Merge(Auto) Commit '9866eb055': fix bad fallback logic external edito…

69971b2

…r logic (google-gemini#17166)

kayang84 mentioned this pull request Jan 25, 2026

## Summary of Changes kayang84/kayang#1

Open

h8920981945 approved these changes Jan 26, 2026

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kuishou68 pushed a commit to iOfficeAI/gemini-cli-pro that referenced this pull request Feb 27, 2026

fix bad fallback logic external editor logic (google-gemini#17166)

b544ba0

cocosheng-g pushed a commit that referenced this pull request May 6, 2026

fix bad fallback logic external editor logic (#17166)

a1620e5

sripasg added the size/xs An extra small PR label Jun 2, 2026

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scidomino commented Jan 21, 2026

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