text/template: check for literals in chain of terms
The current parser ignores obvious errors such as:
{{0.1.E}}
{{true.any}}
{{"hello".wrong}}
{{nil.E}}
The common problem is that a chain is built from
a literal value. It then panics at execution time.
Furthermore, a double dot triggers the same behavior:
{{..E}}
Addresses a TODO left in Tree.operand to catch these
errors at parsing time.
Note that identifiers can include a '.', and pipelines
could return an object which a field can be derived
from (like a variable), so they are excluded from the check.
Fixes #10615
Change-Id: I903706d1c17861b5a8354632c291e73c9c0bc4e1
Reviewed-on: https://go-review.googlesource.com/9621
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/text/template/exec_test.go b/src/text/template/exec_test.go
index 27c74eb..abce27f 100644
--- a/src/text/template/exec_test.go
+++ b/src/text/template/exec_test.go
@@ -527,8 +527,10 @@
{"bug12XE", "{{printf `%T` 0XEE}}", "int", T{}, true},
// Chained nodes did not work as arguments. Issue 8473.
{"bug13", "{{print (.Copy).I}}", "17", tVal, true},
- // Didn't protect against explicit nil in field chains.
- {"bug14", "{{nil.True}}", "", tVal, false},
+ // Didn't protect against nil or literal values in field chains.
+ {"bug14a", "{{(nil).True}}", "", tVal, false},
+ {"bug14b", "{{$x := nil}}{{$x.anything}}", "", tVal, false},
+ {"bug14c", `{{$x := (1.0)}}{{$y := ("hello")}}{{$x.anything}}{{$y.true}}`, "", tVal, false},
}
func zeroArgs() string {
