diff --git a/commit.go b/commit.go
index f259aac..e16246f 100644
--- a/commit.go
+++ b/commit.go
@@ -85,9 +85,7 @@ func (c *Commit) IsImageFile(name string) bool {
 	}
 	buf := make([]byte, 1024)
 	n, _ := dataRc.Read(buf)
-	if n > 0 {
-		buf = buf[:n]
-	}
+	buf = buf[:n]
 	_, isImage := isImageFile(buf)
 	return isImage
 }
diff --git a/git.go b/git.go
index 6114194..71a9a37 100644
--- a/git.go
+++ b/git.go
@@ -10,7 +10,7 @@ import (
 	"time"
 )
 
-const _VERSION = "0.4.1"
+const _VERSION = "0.4.2"
 
 func Version() string {
 	return _VERSION