v2: nil-guard Application.Quit so pre-Run shutdown doesn't panic (#5468)

a.application is only set inside Run() once app.CreateApp succeeds.
Calling Quit() before Run() (or after Run() failed early at CreateApp)
hits a nil receiver inside the inner closure and crashes the host
process. Fix from the issue: guard the Shutdown() call.

Closes #5452

Signed-off-by: Charlie Tonneslan <cst0520@gmail.com>
Co-authored-by: Lea Anthony <lea.anthony@gmail.com>

Author: c-tonneslan

v2/pkg/application/application.go

@@ -74,10 +74,16 @@ func (a *Application) Run() error {
 	return err
 }
 
-// Quit will shut down the application
+// Quit will shut down the application.
+//
+// Safe to call before Run, or after Run returns early (e.g. CreateApp failed).
+// Without the nil guard, Quit() in those situations dereferences an unset
+// a.application and crashes (#5452).
 func (a *Application) Quit() {
 	a.shutdown.Do(func() {
-		a.application.Shutdown()
+		if a.application != nil {
+			a.application.Shutdown()
+		}
 	})
 }
 

website/src/pages/changelog.mdx

@@ -14,6 +14,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed nil pointer crash in `application.Quit` when called before `Run` or after `Run` returned early [#5452](https://github.com/wailsapp/wails/issues/5452) by @c-tonneslan
+
 ## v2.12.0 - 2026-03-26
 
 ### Fixed