text/template: detect unmatched else at parsing time
An unmatched {{else}} should trigger a parsing error.
The top level parser is able to issue an error in case
of unmatched {{end}}. It does it a posteriori (i.e. after having
parsed the action).
Extend this behavior to also check for unmatched {{else}}
Fixes #10611
Change-Id: I1d4f433cc64e11bea5f4d61419ccc707ac01bb1d
Reviewed-on: https://go-review.googlesource.com/9620
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/text/template/parse/parse.go b/src/text/template/parse/parse.go
index af33880..d0efcbf 100644
--- a/src/text/template/parse/parse.go
+++ b/src/text/template/parse/parse.go
@@ -288,11 +288,12 @@
}
t.backup2(delim)
}
- n := t.textOrAction()
- if n.Type() == nodeEnd {
+ switch n := t.textOrAction(); n.Type() {
+ case nodeEnd, nodeElse:
t.errorf("unexpected %s", n)
+ default:
+ t.Root.append(n)
}
- t.Root.append(n)
}
return nil
}
diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go
index 4a504fa..faac06f 100644
--- a/src/text/template/parse/parse_test.go
+++ b/src/text/template/parse/parse_test.go
@@ -230,6 +230,9 @@
// Errors.
{"unclosed action", "hello{{range", hasError, ""},
{"unmatched end", "{{end}}", hasError, ""},
+ {"unmatched else", "{{else}}", hasError, ""},
+ {"unmatched else after if", "{{if .X}}hello{{end}}{{else}}", hasError, ""},
+ {"multiple else", "{{if .X}}1{{else}}2{{else}}3{{end}}", hasError, ""},
{"missing end", "hello{{range .x}}", hasError, ""},
{"missing end after else", "hello{{range .x}}{{else}}", hasError, ""},
{"undefined function", "hello{{undefined}}", hasError, ""},
