From caa462137a41f68bbb6d604ab6fa14c3d89fca5b Mon Sep 17 00:00:00 2001
From: Rob Pike <r@golang.org>
Date: Thu, 12 Sep 2013 13:22:56 +1000
Subject: [PATCH] text/template: catch unmatched right delimiter It was simply
 a missing error case: when scanning plain text outside of an action, a right
 delimiter should be an error.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/13468045
---
 src/pkg/text/template/parse/lex.go        | 4 ++++
 src/pkg/text/template/parse/lex_test.go   | 3 +++
 src/pkg/text/template/parse/parse_test.go | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/pkg/text/template/parse/lex.go b/src/pkg/text/template/parse/lex.go
index 1674aaf9cd..690497d645 100644
--- a/src/pkg/text/template/parse/lex.go
+++ b/src/pkg/text/template/parse/lex.go
@@ -217,6 +217,10 @@ func lexText(l *lexer) stateFn {
 			}
 			return lexLeftDelim
 		}
+		// Check for right after left in case they're the same.
+		if strings.HasPrefix(l.input[l.pos:], l.rightDelim) {
+			return l.errorf("unmatched right delimiter")
+		}
 		if l.next() == eof {
 			break
 		}
diff --git a/src/pkg/text/template/parse/lex_test.go b/src/pkg/text/template/parse/lex_test.go
index ae90ae407b..e72e07f269 100644
--- a/src/pkg/text/template/parse/lex_test.go
+++ b/src/pkg/text/template/parse/lex_test.go
@@ -340,6 +340,9 @@ var lexTests = []lexTest{
 		{itemText, 0, "hello-"},
 		{itemError, 0, `comment ends before closing delimiter`},
 	}},
+	{"unmatched right delimiter", "hello-{.}}-world", []item{
+		{itemError, 0, `unmatched right delimiter`},
+	}},
 }
 
 // collect gathers the emitted items into a slice.
diff --git a/src/pkg/text/template/parse/parse_test.go b/src/pkg/text/template/parse/parse_test.go
index c35f4ac5df..049e65c7d3 100644
--- a/src/pkg/text/template/parse/parse_test.go
+++ b/src/pkg/text/template/parse/parse_test.go
@@ -312,7 +312,7 @@ var isEmptyTests = []isEmptyTest{
 	{"spaces only", " \t\n \t\n", true},
 	{"definition", `{{define "x"}}something{{end}}`, true},
 	{"definitions and space", "{{define `x`}}something{{end}}\n\n{{define `y`}}something{{end}}\n\n", true},
-	{"definitions and text", "{{define `x`}}something{{end}}\nx\n{{define `y`}}something{{end}}\ny\n}}", false},
+	{"definitions and text", "{{define `x`}}something{{end}}\nx\n{{define `y`}}something{{end}}\ny\n", false},
 	{"definition and action", "{{define `x`}}something{{end}}{{if 3}}foo{{end}}", false},
 }
 
-- 
2.50.0