text/template: Call using string as type int (original) (raw)

The following program crashes with panic:

package main

import ( "errors" "html/template" "io/ioutil" )

func main() { data := "{{R html}}" t, err := template.New("foo").Funcs(funcs).Parse(string(data)) if err != nil { if t != nil { panic("non nil template on error") } return } d := &Data{ A: 42, B: "foo", C: []int{1, 2, 3}, D: map[int]string{1: "foo", 2: "bar"}, E: Data1{42, "foo"}, } t.Execute(ioutil.Discard, d) return }

type Data struct { A int B string C []int D map[int]string E Data1 }

type Data1 struct { A int B string }

func (Data1) Q() string { return "foo" }

func (Data1) W() (string, error) { return "foo", nil }

func (Data1) E() (string, error) { return "foo", errors.New("Data.E error") }

func (Data1) R(v int) (string, error) { return "foo", nil }

func (Data1) T(s string) (string, error) { return s, nil }

var funcs = map[string]interface{}{ "Q": func1, "W": func2, "E": func3, "R": func4, "T": func5, "Y": func6, "U": func7, "I": func8, }

func func1(s string) string { return s }

func func2(s string) (string, error) { return s, nil }

func func3(s string) (string, error) { return s, errors.New("func3 error") }

func func4(v int) int { return v }

func func5(v int) (int, error) { return v, nil }

func func6() int { return 42 }

func func7() (int, error) { return 42, nil }

func func8() (int, error) { return 42, errors.New("func8 error") }

panic: reflect: Call using string as type int [recovered]
    panic: reflect: Call using string as type int

goroutine 1 [running]:
text/template.errRecover(0xc208043e50)
    src/text/template/exec.go:104 +0x146
reflect.Value.call(0x55bf00, 0x62eaa0, 0x13, 0x5bf4f0, 0x4, 0xc20800a4c0, 0x1, 0x1, 0x0, 0x0, ...)
    src/reflect/value.go:369 +0x749
reflect.Value.Call(0x55bf00, 0x62eaa0, 0x13, 0xc20800a4c0, 0x1, 0x1, 0x0, 0x0, 0x0)
    src/reflect/value.go:300 +0xb4
text/template.(*state).evalCall(0xc208043de0, 0x52fc40, 0xc2080122d0, 0x16, 0x55bf00, 0x62eaa0, 0x13, 0x7f97307ee3b0, 0xc2080148a0, 0xc20800e5b2, ...)
    src/text/template/exec.go:592 +0xb04
text/template.(*state).evalFunction(0xc208043de0, 0x52fc40, 0xc2080122d0, 0x16, 0xc2080148d0, 0x7f97307ee3b0, 0xc2080148a0, 0xc208014930, 0x2, 0x3, ...)
    src/text/template/exec.go:473 +0x427
text/template.(*state).evalCommand(0xc208043de0, 0x52fc40, 0xc2080122d0, 0x16, 0xc2080148a0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
    src/text/template/exec.go:370 +0x1ec
text/template.(*state).evalPipeline(0xc208043de0, 0x52fc40, 0xc2080122d0, 0x16, 0xc208012280, 0x0, 0x0, 0x0)
    src/text/template/exec.go:343 +0x184
text/template.(*state).walk(0xc208043de0, 0x52fc40, 0xc2080122d0, 0x16, 0x7f97307ee2d8, 0xc208014960)
    src/text/template/exec.go:178 +0x138
text/template.(*state).walk(0xc208043de0, 0x52fc40, 0xc2080122d0, 0x16, 0x7f97307ee320, 0xc208014870)
    src/text/template/exec.go:186 +0x78b
text/template.(*Template).Execute(0xc208010440, 0x7f97307ee1f0, 0xc20800e4f0, 0x52fc40, 0xc2080122d0, 0x0, 0x0)
    src/text/template/exec.go:141 +0x3ea
html/template.(*Template).Execute(0xc208014780, 0x7f97307ee1f0, 0xc20800e4f0, 0x52fc40, 0xc2080122d0, 0x0, 0x0)
    src/html/template/template.go:104 +0x9d
main.main()
    /tmp/ht.go:26 +0x543

on commit abb818b