2 files changed, 34 insertions, 6 deletions
diff --git a/src/text/template/parse/lex.go b/src/text/template/parse/lex.go
index 40d0411121..078f714ccf 100644
--- a/src/text/template/parse/lex.go
+++ b/src/text/template/parse/lex.go
@@ -541,13 +541,25 @@ func (l *lexer) atTerminator() bool {
 	case eof, '.', ',', '|', ':', ')', '(':
 		return true
 	}
-	// Does r start the delimiter? This can be ambiguous (with delim=="//", $x/2 will
-	// succeed but should fail) but only in extremely rare cases caused by willfully
-	// bad choice of delimiter.
-	if rd, _ := utf8.DecodeRuneInString(l.rightDelim); rd == r {
-		return true
+	// Are we at a right delimiter? TODO: This is harder than it should be
+	// because lookahead is only one rune.
+	rightDelim := l.rightDelim
+	defer func(pos Pos, line int) {
+		l.pos = pos
+		l.line = line
+	}(l.pos, l.line)
+	for len(rightDelim) > 0 {
+		rNext := l.next()
+		if rNext == eof {
+			return false
+		}
+		rDelim, size := utf8.DecodeRuneInString(rightDelim)
+		if rNext != rDelim {
+			return false
+		}
+		rightDelim = rightDelim[size:]
 	}
-	return false
+	return true
 }
 
 // lexChar scans a character constant. The initial quote is already
diff --git a/src/text/template/parse/lex_test.go b/src/text/template/parse/lex_test.go
index df6aabffb2..fcb7e8eacd 100644
--- a/src/text/template/parse/lex_test.go
+++ b/src/text/template/parse/lex_test.go
@@ -469,6 +469,22 @@ func TestDelims(t *testing.T) {
 	}
 }
 
+func TestDelimsAlphaNumeric(t *testing.T) {
+	test := lexTest{"right delimiter with alphanumeric start", "{{hub .host hub}}", []item{
+		mkItem(itemLeftDelim, "{{hub"),
+		mkItem(itemSpace, " "),
+		mkItem(itemField, ".host"),
+		mkItem(itemSpace, " "),
+		mkItem(itemRightDelim, "hub}}"),
+		tEOF,
+	}}
+	items := collect(&test, "{{hub", "hub}}")
+
+	if !equal(items, test.items, false) {
+		t.Errorf("%s: got\n\t%v\nexpected\n\t%v", test.name, items, test.items)
+	}
+}
+
 var lexPosTests = []lexTest{
 	{"empty", "", []item{{itemEOF, 0, "", 1}}},
 	{"punctuation", "{{,@%#}}", []item{