make sure all caught panics have a stack with them

errors.go

@@ -58,12 +58,13 @@ func (a *App) PanicHandler(next Handler) Handler {
 			if r != nil { //catch
 				switch t := r.(type) {
 				case error:
-					err = errors.WithStack(t)
+					err = t
 				case string:
-					err = errors.WithStack(errors.New(t))
+					err = errors.New(t)
 				default:
 					err = errors.New(fmt.Sprint(t))
 				}
+				err = errors.WithStack(err)
 				eh := a.ErrorHandlers.Get(500)
 				eh(500, err, c)
 			}

errors_test.go

@@ -0,0 +1,43 @@
+package buffalo
+
+import (
+	"testing"
+
+	"github.com/markbates/willie"
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_PanicHandler(t *testing.T) {
+	app := New(Options{})
+	app.GET("/string", func(c Context) error {
+		panic("string boom")
+	})
+	app.GET("/error", func(c Context) error {
+		panic(errors.New("error boom"))
+	})
+
+	table := []struct {
+		path     string
+		expected string
+	}{
+		{"/string", "string boom"},
+		{"/error", "error boom"},
+	}
+
+	const stack = `github.com/gobuffalo/buffalo.(*App).PanicHandler`
+
+	w := willie.New(app)
+	for _, tt := range table {
+		t.Run(tt.path, func(st *testing.T) {
+			r := require.New(st)
+
+			res := w.HTML(tt.path).Get()
+			r.Equal(500, res.Code)
+
+			body := res.Body.String()
+			r.Contains(body, tt.expected)
+			r.Contains(body, stack)
+		})
+	}
+}