[release-branch.go1] text/template: pipelined arg was not typechecked

««« backport c007925a75c6
text/template: pipelined arg was not typechecked
Without this fix, an erroneous template causes a panic; should be caught safely.
The bug did not affect correct templates.

Fixes #3267.

R=golang-dev, dsymonds, rsc
CC=golang-dev
https://golang.org/cl/5900065
»»»

diff --git a/src/pkg/text/template/exec.go b/src/pkg/text/template/exec.go
index 9a720cf43e3743cf8db17423c4e995f5a0f42791..feb434a3be97f115a5047ae33156dda6dbbe2cc3 100644 (file)
--- a/src/pkg/text/template/exec.go
+++ b/src/pkg/text/template/exec.go
@@ -491,7 +491,11 @@ func (s *state) evalCall(dot, fun reflect.Value, name string, args []parse.Node,
        }
        // Add final value if necessary.
        if final.IsValid() {
-               argv[i] = final
+               t := typ.In(typ.NumIn() - 1)
+               if typ.IsVariadic() {
+                       t = t.Elem()
+               }
+               argv[i] = s.validateType(final, t)
        }
        result := fun.Call(argv)
        // If we have an error that is not nil, stop execution and return that error to the caller.
@@ -507,6 +511,7 @@ func (s *state) validateType(value reflect.Value, typ reflect.Type) reflect.Valu
                switch typ.Kind() {
                case reflect.Interface, reflect.Ptr, reflect.Chan, reflect.Map, reflect.Slice, reflect.Func:
                        // An untyped nil interface{}. Accept as a proper nil value.
+                       // TODO: Can we delete the other types in this list? Should we?
                        value = reflect.Zero(typ)
                default:
                        s.errorf("invalid value; expected %s", typ)

diff --git a/src/pkg/text/template/exec_test.go b/src/pkg/text/template/exec_test.go
index 5446027ff7ad0ae78425871a12fb81345bd57089..37d25f470cd5890c043a834995eca7f4f5ab5f0b 100644 (file)
--- a/src/pkg/text/template/exec_test.go
+++ b/src/pkg/text/template/exec_test.go
@@ -470,6 +470,9 @@ var execTests = []execTest{
        {"bug7a", "{{3 2}}", "", tVal, false},
        {"bug7b", "{{$x := 1}}{{$x 2}}", "", tVal, false},
        {"bug7c", "{{$x := 1}}{{3 | $x}}", "", tVal, false},
+       // Pipelined arg was not being type-checked.
+       {"bug8a", "{{3|oneArg}}", "", tVal, false},
+       {"bug8b", "{{4|dddArg 3}}", "", tVal, false},
 }
 
 func zeroArgs() string {
@@ -480,6 +483,10 @@ func oneArg(a string) string {
        return "oneArg=" + a
 }
 
+func dddArg(a int, b ...string) string {
+       return fmt.Sprintln(a, b)
+}
+
 // count returns a channel that will deliver n sequential 1-letter strings starting at "a"
 func count(n int) chan string {
        if n == 0 {
@@ -504,6 +511,7 @@ func testExecute(execTests []execTest, template *Template, t *testing.T) {
        b := new(bytes.Buffer)
        funcs := FuncMap{
                "count":    count,
+               "dddArg":   dddArg,
                "oneArg":   oneArg,
                "typeOf":   typeOf,
                "vfunc":    vfunc,