fix(router): removing a route with a custom method panics

[vishr]

Router.Remove panics with a nil pointer dereference for a route registered with a custom method, for example e.Add("PURGE", "/cache", h) followed by e.Router().Remove("PURGE", "/cache"). ConcurrentRouter.Remove delegates to it, so it panics too.

Cause: Remove clears the handler with setHandler(method, nil). Methods with their own field (GET, POST, …) just set it to nil. Custom methods fall through to the default branch of routeMethods.set, which read r.handler on the nil route.

Fix: treat a nil route like a nil handler and delete the anyOther entry. Remove is the only caller that passes nil.

Test: TestDefaultRouter_RemoveCustomMethod covers two cases:

• Removing a custom-method route from a path that keeps its GET route: the Routes list is updated, a later PURGE request gets 405, and PURGE is gone from the Allow header.
• Removing the only route on a path: a later request gets 404.

It panics on master and passes here. go test -race ./..., go vet, staticcheck and golint pass.

v4 has no Router.Remove, so this is v5 only.

[Copilot]

Copilot review overview

🟢 Approval recommended

The narrow nil guard fixes the panic while preserving existing behavior, with regression coverage for both removal outcomes.

Review effort: Balanced
Findings: None

What changed in this PR

Fixes the Echo v5 router panic when removing a route registered with a custom HTTP method.

Changes:

• Handles nil routes before accessing their handlers.
• Adds regression coverage for removal with and without another route remaining.

File	Description
router.go	Guards against nil routes when deleting custom methods.
router_test.go	Verifies route listings, 405/404 responses, and the Allow header after removal.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.