From ee2ee025993421b243ef668e4d4ee395a5201820 Mon Sep 17 00:00:00 2001
From: Junegunn Choi <junegunn.c@gmail.com>
Date: Mon, 5 Jan 2015 19:32:44 +0900
Subject: [PATCH] Fix index out of bounds error during Transform

---
 src/tokenizer.go      | 8 +++++++-
 src/tokenizer_test.go | 4 ++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/tokenizer.go b/src/tokenizer.go
index c187529..bc1ca3a 100644
--- a/src/tokenizer.go
+++ b/src/tokenizer.go
@@ -186,7 +186,13 @@ func Transform(tokens []Token, withNth []Range) *Transformed {
 			}
 		}
 		whole += part
-		transTokens[idx] = Token{&part, tokens[minIdx].prefixLength}
+		var prefixLength int
+		if minIdx < numTokens {
+			prefixLength = tokens[minIdx].prefixLength
+		} else {
+			prefixLength = 0
+		}
+		transTokens[idx] = Token{&part, prefixLength}
 	}
 	return &Transformed{
 		whole: &whole,
diff --git a/src/tokenizer_test.go b/src/tokenizer_test.go
index ed77efe..1ae0c7e 100644
--- a/src/tokenizer_test.go
+++ b/src/tokenizer_test.go
@@ -95,3 +95,7 @@ func TestTransform(t *testing.T) {
 		}
 	}
 }
+
+func TestTransformIndexOutOfBounds(t *testing.T) {
+	Transform([]Token{}, splitNth("1"))
+}