Avoid checking date header of web requests by properly applying generic handlers (#2914)

vendor/github.com/urfave/negroni/recovery.go

@@ -0,0 +1,65 @@
+package negroni
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"runtime"
+	"runtime/debug"
+)
+
+// Recovery is a Negroni middleware that recovers from any panics and writes a 500 if there was one.
+type Recovery struct {
+	Logger           ALogger
+	PrintStack       bool
+	ErrorHandlerFunc func(interface{})
+	StackAll         bool
+	StackSize        int
+}
+
+// NewRecovery returns a new instance of Recovery
+func NewRecovery() *Recovery {
+	return &Recovery{
+		Logger:     log.New(os.Stdout, "[negroni] ", 0),
+		PrintStack: true,
+		StackAll:   false,
+		StackSize:  1024 * 8,
+	}
+}
+
+func (rec *Recovery) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	defer func() {
+		if err := recover(); err != nil {
+			if rw.Header().Get("Content-Type") == "" {
+				rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
+			}
+
+			rw.WriteHeader(http.StatusInternalServerError)
+
+			stack := make([]byte, rec.StackSize)
+			stack = stack[:runtime.Stack(stack, rec.StackAll)]
+
+			f := "PANIC: %s\n%s"
+			rec.Logger.Printf(f, err, stack)
+
+			if rec.PrintStack {
+				fmt.Fprintf(rw, f, err, stack)
+			}
+
+			if rec.ErrorHandlerFunc != nil {
+				func() {
+					defer func() {
+						if err := recover(); err != nil {
+							rec.Logger.Printf("provided ErrorHandlerFunc panic'd: %s, trace:\n%s", err, debug.Stack())
+							rec.Logger.Printf("%s\n", debug.Stack())
+						}
+					}()
+					rec.ErrorHandlerFunc(err)
+				}()
+			}
+		}
+	}()
+
+	next(rw, r)
+}