fix(v3/linux): release WebKitURISchemeRequest on the GTK main context by leaanthony · Pull Request #5566 · wailsapp/wails

leaanthony · 2026-06-10T21:27:50Z

Description

request.Close() runs on the assetserver goroutine (AssetServer.processWebViewRequest → webViewAssetRequest.Close) and dropped what may be the last reference to the WebKitURISchemeRequest there. Finalizing a WebKit GObject off the GTK main thread violates WebKitGTK's threading rules and intermittently kills long-running apps with:

SIGSEGV: segmentation violation
signal arrived during cgo execution
_Cfunc_g_object_unref(...)
(*request).Close(...)  request_linux_gtk3.go:80

Fix

Schedule the unref onto the default GMainContext with g_main_context_invoke instead of unreffing inline. Applied to both the GTK3 (webkit2gtk-4.1) and GTK4 (webkitgtk-6.0) request implementations, which share the identical pattern.

g_object_ref in NewRequest is intentionally unchanged: GObject ref/unref are atomic and thread-safe in themselves — only the finalization triggered by dropping the final reference is main-thread-only. g_main_context_invoke runs the callback immediately if the caller already owns the main context, so this is also correct if Close ever runs on the UI thread.

Verification

go build/go vet with -tags gtk3 and default gtk4 tags pass on Linux (Ubuntu, WebKitGTK 4.1 + 6.0).
go test for ./internal/assetserver/... and ./pkg/application (under xvfb, gtk3 tags) passes.
A deterministic unit test isn't feasible here — the crash needs a live WebKit webview finalizing a real WebKitURISchemeRequest under load. The equivalent patch (unref via g_main_context_invoke) was validated by the reporter in production over multi-day runs (see [v3][Linux][GTK3] Intermittent SIGSEGV in assetserver when closing WebKitURISchemeRequest (g_object_unref) #5557).

Fixes #5557

Type of change

Bug fix (non-breaking change which fixes an issue)

Checklist:

My code follows the general coding style of this project
I have updated v3/UNRELEASED_CHANGELOG.md

Summary by CodeRabbit

Bug Fixes
- Fixed an intermittent crash on Linux that could occur when closing in-app web requests, improving stability during asset serving.
Documentation
- Added a changelog entry documenting the fix.

request.Close() runs on the assetserver goroutine and dropped what may be the last reference to the WebKitURISchemeRequest there. Finalizing a WebKit GObject off the GTK main thread violates WebKitGTK's threading rules and intermittently crashes long-running apps with a SIGSEGV in g_object_unref during cgo execution. Schedule the unref onto the default GMainContext with g_main_context_invoke instead, in both the GTK3 (webkit2gtk-4.1) and GTK4 (webkitgtk-6.0) request implementations, which share the pattern. g_object_ref in NewRequest is unchanged: ref/unref themselves are atomic; only the finalization triggered by the final unref is main-thread-only. Verified: gtk3 and gtk4 builds plus assetserver/application test suites pass on Linux (Ubuntu, WebKitGTK 4.1/6.0). The equivalent workaround was validated in production by the reporter over multi-day runs. Fixes #5557

coderabbitai · 2026-06-10T21:28:03Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 97a6dfb1-1e73-4363-aebb-e493c707b94a

📥 Commits

Reviewing files that changed from the base of the PR and between 460175a and f71313e.

📒 Files selected for processing (2)

v3/internal/assetserver/webview/request_linux.go
v3/internal/assetserver/webview/request_linux_gtk3.go

🚧 Files skipped from review as they are similar to previous changes (2)

v3/internal/assetserver/webview/request_linux.go
v3/internal/assetserver/webview/request_linux_gtk3.go

Walkthrough

C helper functions were added to Linux WebKit request handlers to schedule g_object_unref on the GTK main context via g_main_context_invoke, and both (*request).Close() implementations now call that helper. UNRELEASED_CHANGELOG.md documents the fix referencing #5557.

Changes

GTK main context marshalling for WebKit request finalization

Layer / File(s)	Summary
Add C helpers to invoke g_object_unref on GTK main context `v3/internal/assetserver/webview/request_linux.go`, `v3/internal/assetserver/webview/request_linux_gtk3.go`	Adds C helper functions that schedule a callback with `g_main_context_invoke` which performs `g_object_unref` on a `WebKitURISchemeRequest` (includes null checks and one-shot callback semantics).
Call C helper from Close() `v3/internal/assetserver/webview/request_linux.go`, `v3/internal/assetserver/webview/request_linux_gtk3.go`	Replaces direct `g_object_unref` calls in both `(*request).Close()` implementations with `releaseRequestOnMainThread(r.req)` so the unref runs on the GTK main thread.
Changelog documentation `v3/UNRELEASED_CHANGELOG.md`	Adds an UNRELEASED_CHANGELOG.md entry noting the intermittent Linux `SIGSEGV` fix and that final `g_object_unref` is marshalled onto the GTK main context via `g_main_context_invoke` (refs `#5557`).

🎯 3 (Moderate) | ⏱️ ~20 minutes

Bug, go, v3, Linux

🐰 I hopped through threads both near and far,
Found an unref that tripped on where GTK are,
I marshalled it gently to the main thread's light,
Now objects fall safe in the day and night,
Hooray — no more SIGSEGV fright! 🎉

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main fix: releasing WebKitURISchemeRequest on the GTK main context to fix threading issues on Linux.
Description check	✅ Passed	The PR description is comprehensive, explaining the problem, solution, rationale, verification, and references the fixed issue. However, the Type of change and Checklist sections were completed but testing platform checkboxes (Windows, macOS, Linux) and wails doctor output were not provided.
Linked Issues check	✅ Passed	The PR successfully addresses all objectives from issue `#5557`: prevents intermittent SIGSEGVs by scheduling g_object_unref on the GTK main context via g_main_context_invoke, applies the fix to both GTK3 and GTK4 implementations, and includes proper verification steps.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing issue `#5557`: modifications to request_linux.go and request_linux_gtk3.go implement the threading fix, and the changelog entry documents the fix. No unrelated changes are present.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

📝 Generate docstrings

Create stacked PR
Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch fix/gtk3-request-unref-5557

Warning

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🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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Copilot

Pull request overview

Fixes an intermittent Linux crash in the v3 assetserver WebView request cleanup path by ensuring WebKitURISchemeRequest is unref’d on the GTK main context (avoiding off-main-thread finalization of a WebKit GObject), and documents the fix in the unreleased changelog.

Changes:

Marshal WebKitURISchemeRequest final g_object_unref onto the default GMainContext via g_main_context_invoke for GTK4 (webkitgtk-6.0) builds.
Apply the same main-context unref scheduling for GTK3 (webkit2gtk-4.1) builds.
Add an unreleased changelog entry describing the crash fix and linking to #5557.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
v3/internal/assetserver/webview/request_linux.go	Dispatches request unref onto the GTK main context for GTK4 builds to prevent off-thread finalization.
v3/internal/assetserver/webview/request_linux_gtk3.go	Mirrors the same main-context unref scheduling for GTK3 builds.
v3/UNRELEASED_CHANGELOG.md	Records the Linux SIGSEGV fix and references #5557.

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Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings June 10, 2026 21:27

Copilot started reviewing on behalf of leaanthony June 10, 2026 21:27 View session

Copilot AI reviewed Jun 10, 2026

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Comment thread v3/internal/assetserver/webview/request_linux.go

Comment thread v3/internal/assetserver/webview/request_linux_gtk3.go

leaanthony and others added 3 commits June 12, 2026 21:10

Potential fix for pull request finding

74360d5

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Potential fix for pull request finding

f71313e

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Merge branch 'master' into fix/gtk3-request-unref-5557

639645f

leaanthony merged commit e094d72 into master Jun 13, 2026
12 of 15 checks passed

leaanthony deleted the fix/gtk3-request-unref-5557 branch June 13, 2026 03:13

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fix(v3/linux): release WebKitURISchemeRequest on the GTK main context#5566

fix(v3/linux): release WebKitURISchemeRequest on the GTK main context#5566
leaanthony merged 4 commits into
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fix/gtk3-request-unref-5557

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Description

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leaanthony commented Jun 10, 2026 •

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