fix: avoid panic in init godeltaprof/http/pprof for go 1.23 (#119)

* fix: avoid panic in init godeltaprof/http/pprof

* simplify: just use "GET " all the time on go 1.22

Author: korniltsev

godeltaprof/http/pprof/pprof.go

@@ -21,9 +21,10 @@ type deltaProfiler interface {
 }
 
 func init() {
-	http.HandleFunc("/debug/pprof/delta_heap", Heap)
-	http.HandleFunc("/debug/pprof/delta_block", Block)
-	http.HandleFunc("/debug/pprof/delta_mutex", Mutex)
+	prefix := routePrefix()
+	http.HandleFunc(prefix+"/debug/pprof/delta_heap", Heap)
+	http.HandleFunc(prefix+"/debug/pprof/delta_block", Block)
+	http.HandleFunc(prefix+"/debug/pprof/delta_mutex", Mutex)
 }
 
 func Heap(w http.ResponseWriter, r *http.Request) {

godeltaprof/http/pprof/pprof_go21.go

@@ -0,0 +1,7 @@
+//go:build !go1.22
+
+package pprof
+
+func routePrefix() string {
+	return ""
+}

godeltaprof/http/pprof/pprof_go22.go

@@ -0,0 +1,10 @@
+//go:build go1.22
+
+package pprof
+
+func routePrefix() string {
+	// As of go 1.23 we will panic if we don't prefix with "GET "
+	// https://github.com/golang/go/blob/9fcffc53593c5cd103630d0d24ef8bd91e17246d/src/net/http/pprof/pprof.go#L98-L97
+	// https://github.com/golang/go/commit/9fcffc53593c5cd103630d0d24ef8bd91e17246d
+	return "GET "
+}