fix(v2): set LANG for pbpaste/pbcopy to prevent clipboard mojibake on macOS by veeceey · Pull Request #5012 · wailsapp/wails

veeceey · 2026-02-23T04:16:30Z

When a Wails app runs as a standalone macOS app (not launched from a terminal), the LANG environment variable is unset. pbpaste then defaults to an ASCII-compatible encoding, which turns non-ASCII clipboard content into garbage.

The fix ensures LANG=en_US.UTF-8 is set in the command's environment before invoking pbpaste/pbcopy, but only when LANG isn't already present — so it won't override anything the user has explicitly set.

Quick terminal demo showing the difference:

$ echo "你好世界 こんにちは" | pbcopy

$ LANG= pbpaste
Test: ???? ?????

$ LANG=en_US.UTF-8 pbpaste
Test: 你好世界 こんにちは

Summary by CodeRabbit

Bug Fixes
- Improved macOS clipboard handling so copied and pasted text preserve UTF‑8 characters and no longer appear garbled in packaged apps.
Documentation
- Added a changelog entry noting the macOS clipboard mojibake fix.

When macOS apps are launched as standalone (not from terminal), the LANG environment variable is unset. This causes pbpaste to default to an ASCII-compatible encoding, resulting in mojibake for non-ASCII clipboard content. Fix by ensuring LANG=en_US.UTF-8 is set in the command environment when it's not already present. Fixes wailsapp#4132

veeceey · 2026-02-23T04:16:39Z

Manual test results (macOS 15, M4)

Verified the fix works by testing pbpaste behavior with and without LANG:

$ echo "你好世界 こんにちは" | pbcopy

# Without LANG (simulates standalone app launch):
$ LANG= pbpaste
Test: ???? ?????

# With LANG=en_US.UTF-8 (what this PR does):
$ LANG=en_US.UTF-8 pbpaste
Test: 你好世界 こんにちは

Also confirmed that go build ./v2/internal/frontend/desktop/darwin/ compiles cleanly.

coderabbitai · 2026-02-23T04:16:53Z

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Review profile: CHILL

Plan: Pro

Run ID: 5feb2fe0-28ed-4416-bb8e-409eff766d80

📥 Commits

Reviewing files that changed from the base of the PR and between cf15fd6 and cd70fbb.

📒 Files selected for processing (1)

website/src/pages/changelog.mdx

📝 Walkthrough

Walkthrough

Adds an ensureUTF8Env helper and applies it to the pbpaste and pbcopy command environments so macOS clipboard reads/writes run with LANG set to en_US.UTF-8 when LANG is unset.

Changes

Cohort / File(s)	Summary
Clipboard UTF-8 Environment Fix `v2/internal/frontend/desktop/darwin/clipboard.go`	Adds `ensureUTF8Env()` helper, imports `os`, and sets `Cmd.Env = ensureUTF8Env(os.Environ())` for both `ClipboardGetText` (pbpaste) and `ClipboardSetText` (pbcopy). Adds explanatory comment about packaged macOS apps and LANG.
Changelog entry `website/src/pages/changelog.mdx`	Adds a changelog line under "Fixed" describing the macOS clipboard mojibake fix and referencing the PR.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Possibly related issues

Incorrect Clipboard Text Encoding when LANG Environment Variable is Empty on macOS #4132: Implements setting LANG=en_US.UTF-8 for pbpaste/pbcopy to prevent mojibake when LANG is empty, matching this change's objective.

Suggested reviewers

makew0rld

Poem

🐇 I nibble at bugs beneath the moonlight,
LANG set to UTF-8, clipboard feels right.
Pastes no longer garble, copies hum bright,
A tiny rabbit hop fixed text’s flight. 🥕

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically summarizes the main change: setting LANG environment variable for pbpaste/pbcopy to prevent mojibake on macOS.
Description check	✅ Passed	The description includes issue reference, problem explanation, solution details, and terminal demonstration. However, the Type of change checkbox and testing configuration sections required by the template are not completed.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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coderabbitai

Actionable comments posted: 1

🧹 Nitpick comments (1)

v2/internal/frontend/desktop/darwin/clipboard.go (1)
14-22: Consider os.LookupEnv for a cleaner, more idiomatic implementation.

os.LookupEnv explicitly distinguishes "not set" from "set to empty" without manual string slicing, and is the standard Go idiom for this pattern:
♻️ Proposed refactor
 func ensureUTF8Env() []string {
 	env := os.Environ()
-	for _, e := range env {
-		if len(e) > 5 && e[:5] == "LANG=" {
-			return env
-		}
+	if _, ok := os.LookupEnv("LANG"); !ok {
+		env = append(env, "LANG=en_US.UTF-8")
 	}
-	return append(env, "LANG=en_US.UTF-8")
+	return env
 }
This also correctly handles the case where LANG is set but empty (keeping the existing empty value rather than creating a duplicate entry), which the current loop misses due to the > 5 boundary.
🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed.

In `@v2/internal/frontend/desktop/darwin/clipboard.go` around lines 14 - 22,
Replace the manual loop in ensureUTF8Env with os.LookupEnv: use
os.LookupEnv("LANG") to detect whether LANG is present (allowing an existing
empty value to be preserved) and, if not present, append "LANG=en_US.UTF-8" to
os.Environ(); ensure you return the original env unchanged when LANG is set
(including empty string) to avoid duplicating entries and to follow Go idioms.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@v2/internal/frontend/desktop/darwin/clipboard.go`:
- Line 17: The guard that checks environment entries uses len(e) > 5 && e[:5] ==
"LANG=" which misses the exact "LANG=" entry; update the check in the loop over
environment entries (the variable e) to use a correct boundary such as len(e) >=
5 && e[:5] == "LANG=" or, better, strings.HasPrefix(e, "LANG=") so entries equal
to "LANG=" are treated as matches and the function will early-return instead of
appending a second LANG variable.

---

Nitpick comments:
In `@v2/internal/frontend/desktop/darwin/clipboard.go`:
- Around line 14-22: Replace the manual loop in ensureUTF8Env with os.LookupEnv:
use os.LookupEnv("LANG") to detect whether LANG is present (allowing an existing
empty value to be preserved) and, if not present, append "LANG=en_US.UTF-8" to
os.Environ(); ensure you return the original env unchanged when LANG is set
(including empty string) to avoid duplicating entries and to follow Go idioms.

Replace manual string slicing with os.LookupEnv which is more idiomatic and correctly handles the edge case where LANG is set to an empty string.

coderabbitai

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Duplicate comments:
In `@v2/internal/frontend/desktop/darwin/clipboard.go`:
- Around line 14-20: The function ensureUTF8Env correctly uses
os.LookupEnv("LANG") to detect presence (including an empty LANG=) and only
appends "LANG=en_US.UTF-8" when absent, so no code change is required; keep the
current implementation (ensureUTF8Env) as-is and approve the change.

leaanthony · 2026-02-27T10:44:04Z

Thanks 🙏 Please could you add an entry to the changelog located at website/src/pages/changelog.mdx?

veeceey · 2026-02-28T06:05:20Z

Added changelog entry. Thanks for the review!

veeceey · 2026-03-15T03:05:12Z

hey, any updates on this? the clipboard mojibake on macOS is a pretty annoying issue for non-ASCII users

leaanthony · 2026-03-17T09:04:38Z

Thanks for your patience! And thanks again for creating this PR🙏

coderabbitai Bot reviewed Feb 23, 2026

View reviewed changes

Comment thread v2/internal/frontend/desktop/darwin/clipboard.go Outdated

fix: use os.LookupEnv for LANG check in ensureUTF8Env

b34587e

Replace manual string slicing with os.LookupEnv which is more idiomatic and correctly handles the edge case where LANG is set to an empty string.

coderabbitai Bot reviewed Feb 23, 2026

View reviewed changes

leaanthony and others added 2 commits February 27, 2026 21:44

Merge branch 'master' into fix/issue-4132-clipboard-encoding

7723840

Add changelog entry for clipboard mojibake fix on macOS

cf15fd6

Merge branch 'master' into fix/issue-4132-clipboard-encoding

4960dc4

Merge branch 'master' into fix/issue-4132-clipboard-encoding

cd70fbb

leaanthony approved these changes Mar 17, 2026

View reviewed changes

leaanthony merged commit 0ce8919 into wailsapp:master Mar 17, 2026
1 of 4 checks passed

BrewTestBot mentioned this pull request Mar 26, 2026

wails 2.12.0 Homebrew/homebrew-core#274338

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veeceey commented Feb 23, 2026 • edited by coderabbitai Bot Loading Uh oh! There was an error while loading. Please reload this page.

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Summary by CodeRabbit

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veeceey commented Feb 23, 2026

Manual test results (macOS 15, M4)

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coderabbitai Bot commented Feb 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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leaanthony commented Feb 27, 2026

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veeceey commented Feb 23, 2026 •

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